Download Optilab rEX User's Guide

Optilab rEX
User’s Guide
(M1500 Rev. D)
WYATT TECHNOLOGY Corporation makes no warranties, either express or implied,
regarding this instrument, computer software package, its merchantability or its fitness
for any particular purpose. The software is provided “as is”, without warranty of any
kind. Furthermore, Wyatt Technology does not warrant, guarantee, or make any representations regarding the use, or the results of the use, of the software or written materials in terms of correctness, accuracy, reliability, currentness, or otherwise. The exclusion
of implied warranties is not permitted by some states, so the above exclusion may not
apply to you.
Copyright © 2005, Wyatt Technology Corporation. All rights reserved.
All rights reserved. No part of this publication may be reproduced, stored in a retrieval
system, or transmitted, in any form by any means, electronic, mechanical, photocopying,
recording, or otherwise, without the prior written permission of Wyatt Technology Corporation.
® DAWN, ASTRA, DNDC, and Optilab are registered trademarks of Wyatt Technology
Corporation.
A variety of U.S. and foreign patents have been issued and/or are pending on various
aspects of the apparatus and methodology implemented by this instrumentation.
Contents
Chapter 1: About the Optilab rEX ........................................... 1-1
1.1 Methods of Measuring Refractive Indexes .................................................. 1-2
1.2 Using This Manual ...................................................................................... 1-3
1.3 Contacting Wyatt Technology ...................................................................... 1-4
Chapter 2: Instrument Description ......................................... 2-1
2.1 Overview ..................................................................................................... 2-2
2.2 Front Panel .................................................................................................. 2-3
2.3 Rear Panel .................................................................................................. 2-4
Chapter 3: Quick Start ............................................................. 3-1
3.1 Setting Up the Optilab rEX .......................................................................... 3-2
Chapter 4: Installation and Setup ........................................... 4-1
4.1 Power and Signal Connections ................................................................... 4-2
4.1.1 Power Connector ............................................................................................4-2
4.1.2 Signal Connectors ...........................................................................................4-2
4.1.3 Communication Connector ..............................................................................4-7
4.2 Fluid Connections ....................................................................................... 4-7
4.3 Dry Nitrogen Connection ............................................................................. 4-8
4.4 Power On and Warm Up ............................................................................. 4-9
4.5 Purging the Optilab rEX .............................................................................. 4-9
4.6 Instrument Stability Check ........................................................................ 4-10
Chapter 5: Using the LCD Display .......................................... 5-1
5.1 Navigating the Optilab rEX Tabs ................................................................. 5-2
5.2 Main Tab ...................................................................................................... 5-3
5.3 aRI Tab ........................................................................................................ 5-4
5.4 Alarms Tab .................................................................................................. 5-5
5.5 System Tab ................................................................................................. 5-7
5.5.1 Constants Dialog .............................................................................................5-9
5.5.2 LED Intensity Dialog ...................................................................................... 5-11
5.6 Communications Tab ................................................................................. 5-13
Chapter 6: Off-Line Measurements......................................... 6-1
6.1 Instrument Calibration ................................................................................. 6-2
6.1.1 General Information and Sample Preparation .................................................6-2
6.1.2 HPLC Pump with Injector ................................................................................6-3
6.1.3 Syringe Pump Infusion ....................................................................................6-3
6.1.4 Collecting Data ................................................................................................6-4
Optilab rEX User’s Guide (M1500 Rev. D)
iii
Contents
6.2 dn/dc Measurement .................................................................................... 6-4
6.3 Absolute Refractive Index Measurement .................................................... 6-5
Chapter 7: In-Line HPLC Detection......................................... 7-1
7.1 Conditions for In-Line Operation ................................................................. 7-2
7.2 Sample Preparation .................................................................................... 7-3
7.3 Measurement .............................................................................................. 7-3
Chapter 8: Service and Maintenance...................................... 8-1
8.1 Replacing the LED/Fiber Light Source ........................................................ 8-2
8.2 Cleaning After a Fluid Leak ........................................................................8-11
8.3 Cleaning the Air Intake Filter ..................................................................... 8-12
8.4 Changing a Fuse ....................................................................................... 8-12
8.5 Optilab rEX Firmware Upgrades ............................................................... 8-13
Chapter 9: Troubleshooting .................................................... 9-1
9.1 Low Light Alarm .......................................................................................... 9-2
9.2 Temperature Will Not Set Below 20 C ......................................................... 9-3
9.3 Noisy Baseline ............................................................................................ 9-4
9.4 Microsoft Windows Encounters Problems ................................................... 9-4
Appendix A: Acronyms and Abbreviations List................... A-1
A.1 Acronyms and Abbreviations ...................................................................... A-2
Appendix B: Operating Principles and Theory..................... B-1
B.1 Basic Principles .......................................................................................... B-2
B.1.1 Conventional Flow Cell ................................................................................. B-2
B.1.2 Optilab rEX Flow Cell ..................................................................................... B-3
B.2 Measurement of the Beam Deflection Angle .............................................. B-4
B.2.1 Conventional Split Photodiode Based Instrument ........................................ B-4
B.2.2 Wyatt Technology Corporation Beam Positioning Technology ...................... B-4
Appendix C: Optilab rEX Specifications ............................... C-1
C.1 Specifications .............................................................................................C-2
Appendix D: Wire Colors ........................................................ D-1
D.1 Earlier Cable Revisions ..............................................................................D-2
Appendix E: Instrument Connectivity ................................... E-1
E.1 Introduction ................................................................................................. E-2
E.2 Components Used ...................................................................................... E-3
E.2.1 Instrument Connections ................................................................................. E-3
E.2.2 LAN Connection ............................................................................................. E-4
E.2.3 Computer Connections .................................................................................. E-4
E.2.4 Crossover Cable ............................................................................................ E-5
E.2.5 Ethernet Cable ............................................................................................... E-5
E.2.6 Ethernet to USB Adapter ............................................................................... E-6
E.2.7 Ethernet Switch .............................................................................................. E-7
iv
Optilab rEX User’s Guide (M1500 Rev. D)
Contents
E.3 Connecting to a LAN ................................................................................... E-8
E.3.1 One Instrument to LAN .................................................................................. E-8
E.3.2 One Instrument and Computer to LAN .......................................................... E-9
E.3.3 Multiple Instruments to LAN ......................................................................... E-10
E.3.4 Multiple Instruments and Computer to LAN ..................................................E-11
E.4 Connecting via USB .................................................................................. E-12
E.4.1 One Instrument to USB via a Crossover Cable ........................................... E-12
E.4.2 One Instrument to USB Using an Ethernet Switch ...................................... E-13
E.4.3 Multiple Instruments to USB ........................................................................ E-14
E.5 Connecting via Ethernet When Not on a LAN .......................................... E-15
E.5.1 One Instrument to Computer Using Crossover Cable ................................. E-15
E.5.2 One Instrument to Computer Using an Ethernet Switch .............................. E-16
E.5.3 Multiple Instruments to Computer Using an Ethernet Switch ...................... E-16
E.6 Instrument Network Settings ..................................................................... E-17
E.7 Accessing Instruments with ASTRA V ...................................................... E-18
E.8 Troubleshooting and Diagnostics ............................................................. E-19
E.8.1 Windows XP Professional Service Pack 2 ................................................... E-19
E.8.2 ASTRA V Settings ....................................................................................... E-19
E.8.3 Verifying Instrument Connections ................................................................ E-19
Appendix F: Warnings ............................................................. F-1
F.1 List of Warnings ........................................................................................... F-2
Index .................................................................................. Index-1
Optilab rEX User’s Guide (M1500 Rev. D)
v
Contents
vi
Optilab rEX User’s Guide (M1500 Rev. D)
1
About the Optilab rEX
This chapter provides a general introduction to the Optilab rEX instrument and an overview of the sections in this manual.
CONTENTS
PAGE
1.1 Methods of Measuring Refractive Indexes ..................................... 1-2
1.2 Using This Manual.......................................................................... 1-3
1.3 Contacting Wyatt Technology ......................................................... 1-4
Optilab rEX User’s Guide (M1500 Rev. D)
1-1
Chapter 1: About the Optilab rEX
1.1 Methods of Measuring Refractive Indexes
For the past four decades, virtually all differential Refractive Index (dRI)
detector manufacturers have used a deflection-based instrument design to
measure the refractive index difference between a reference fluid and a
sample fluid. Wyatt Technology’s Optilab DSP stood alone as an interferometric-based instrument with the ability to cool samples below ambient
temperatures. When the Optilab DSP was introduced, an interferometricbased design was the most sensitive method available for measuring dRI.
However, technology does not remain motionless. Significant advances
over the past five years in nanoscale semiconductor fabrication techniques, linear photodiode array technology, and computer speed have
allowed Wyatt Technology to develop a novel deflection-based dRI instrument that surpasses all current measurement methods.
The Optilab rEX (refractometer with EXtended range) is a deflectionbased instrument that pioneers the use of an array of light sensitive detectors in the measurement of dRI. It has a linear array of 512 photodiodes,
rather than the traditional two photodiodes used by other deflection-based
instruments. This photodiode array allows for unprecedented sensitivity
and range.
With most RI instruments, users must choose a gain setting, which essentially means choosing between good sensitivity over a limited range,
reduced sensitivity over a large range, or some compromise between the
two. The Optilab rEX has no gain settings; the maximum sensitivity exists
over the entire range. Tiny signals and huge signals may be measured
within the same data run. The ability to see both large and small signals
may be quantified by the instrument’s dynamic range (defined as range
divided by noise). The dynamic range of the Optilab rEX is 2.35 million,
literally orders of magnitude greater than any other RI instrument on the
market today.
In addition to the photodiode array, the Optilab rEX contains a new flow
cell design that allows the measurement of a fluid’s absolute Refractive
Index (aRI) in addition to the dRI between two fluids. The aRI of a fluid is
vital for characterizing a system and is a necessary input parameter for
light scattering measurements that determine the molecular mass of molecules in solution.
1-2
Optilab rEX User’s Guide (M1500 Rev. D)
Using This Manual
1.2 Using This Manual
The organization of this manual is as follows:
•
Chapter 2, “Instrument Description”: Describes the Optilab rEX
instrument’s control interfaces and connections.
•
Chapter 3, “Quick Start”: Contains a summary of instructions for
setting up the Optilab rEX quickly and with minimal instruction.
•
Chapter 4, “Installation and Setup”: Provides detailed connection
information for installation and setup.
•
Chapter 5, “Using the LCD Display”: Provides detailed information
on how to use the tabs on the LCD display to control, configure, and
monitor the Optilab rEX.
•
Chapter 6, “Off-Line Measurements”: Describes how to make
static measurements with the Optilab rEX, including instrument calibration, off-line dn/dc measurements, and absolute refractive index
measurements.
•
Chapter 7, “In-Line HPLC Detection”: Describes using the Optilab
rEX as an in-line concentration sensitive detector for HPLC.
•
Chapter 8, “Service and Maintenance”: Provides maintenance and
service instructions.
•
•
Chapter 9, “Troubleshooting”: Provides troubleshooting tips.
•
Appendix B, “Operating Principles and Theory”: Provides a basic
and theoretical description of how the Optilab rEX operates.
•
Appendix C, “Optilab rEX Specifications”: Provides the specifications of the Optilab rEX.
•
Appendix D, “Wire Colors”: Provides information about earlier revisions of the general-purpose cable supplied by Wyatt Technology
Corporation.
•
Appendix E, “Instrument Connectivity”: Provides details about
connecting the Optilab rEX to a computer.
•
Appendix F, “Warnings”: Lists warnings to be aware of when using
the Optilab rEX.
•
Index: Provides lookup assistance.
Appendix A, “Acronyms and Abbreviations List”: Contains a list
of acronyms and abbreviations used in this manual.
Optilab rEX User’s Guide (M1500 Rev. D)
1-3
Chapter 1: About the Optilab rEX
1.3 Contacting Wyatt Technology
We solicit and encourage questions and comments about this manual and
the Optilab rEX instrument. Please contact:
Technical Support Department
Wyatt Technology Corporation
6300 Hollister Avenue
Santa Barbara, CA 93117
Telephone:
FAX:
E-mail:
1-4
(805) 681-9009
(805) 681-0123
[email protected]
Optilab rEX User’s Guide (M1500 Rev. D)
2
Instrument Description
This chapter provides an overview of the Optilab rEX features.
CONTENTS
PAGE
2.1 Overview......................................................................................... 2-2
2.2 Front Panel ..................................................................................... 2-3
2.3 Rear Panel...................................................................................... 2-4
Optilab rEX User’s Guide (M1500 Rev. D)
2-1
Chapter 2: Instrument Description
2.1 Overview
The Optilab rEX measures the dRI between the current liquid sample
stream and a liquid (usually clean solvent) previously stored as a reference. The dRI is measured at a fixed wavelength determined by a Light
Emitting Diode (LED)/fiber light source. The light source consists of a
high-powered LED coupled to a special optical fiber. This “pigtail” configuration allows you to easily replace the light source. If you want to change
the measurement wavelength, installing a “pigtail” with a different wavelength accomplishes this.
The dRI data can be read from the LCD display, the analog output
channel, or digitally through the Ethernet port. Since the dRI of liquids
depends critically on temperature, the instrument has a system that precisely regulates the temperature of both the flow cell and the optics.
In addition to the dRI between two liquids, with the same liquid present in
the sample and reference chambers, the Optilab rEX measures the aRI of
that liquid.
For a more detailed theoretical description, see Appendix B, “Operating
Principles and Theory”.
2-2
Optilab rEX User’s Guide (M1500 Rev. D)
Front Panel
2.2 Front Panel
The front panel, see Figure 2-1, provides fluid connections for the Optilab
rEX and all of the necessary functions and displays for operating the
instrument and monitoring data.
Front Panel Door
Liquid Leak Port
LCD Display
Keypad
Power Switch
Figure 2-1: Front panel
Front Panel Door: The front panel door opens to provide access to the IN
and OUT fluid connections for the Optilab rEX.
LCD Display: The LCD display provides a full-color, high-resolution user
interface to the Optilab rEX. It allows you to monitor, control and configure the instrument. Chapter 5, “Using the LCD Display” describes all of
the tabs available on the LCD display and their functions.
Keypad: The keypad allows you to control the LCD display. “Navigating
the Optilab rEX Tabs” on page 5-2 describes how to use the keypad to
navigate through the LCD display tabs.
IN/OUT Fluid Connectors: Fluid comes into the Optilab rEX through
the IN port, and exits through the OUT port. The Optilab rEX should be
connected last in line if other detectors are connected in series.
Liquid Leak Port: The liquid leak port provides an exit for any liquid
that leaks from internal or external fittings. The Teflon tubing provided
may be fit over this tubing and directed to a fluid waste bottle. When a
liquid leak occurs, an internal liquid sensor activates an alarm shown on
the LCD display (see “Alarms Tab” on page 5-5), and activates an Alarm
Out signal that may be used to shut off a pump.
Power Switch: The power switch turns instrument power On and Off.
Optilab rEX User’s Guide (M1500 Rev. D)
2-3
Chapter 2: Instrument Description
2.3 Rear Panel
The rear panel, see Figure 2-2, provides access for power, signal connections, the cooling fan, air filter, the exhaust fan, and a nitrogen purge port.
Air Intake Fan
Power Connector
Signal Connectors
Air Exhaust Fan
Communications Connector
Nitrogen Purge Port
Figure 2-2: Rear panel
Air Intake and Exhaust Fans: The fans help to keep the instrument
electronics at a constant temperature.
Signal Connectors: There are 10 RJ-12 connectors that provide connections to Transistor-Transistor Logic (TTL) inputs and outputs, Analog
input and output, Auto Inject input and output, and a solenoid drive
output. For a description of the signal connectors, see “Power and Signal
Connections” on page 4-2.
Power Connector: Provides power to the instrument. See “Power and
Signal Connections” on page 4-2 for a complete description of the Optilab
rEX’s power requirements.
Communications Connector: The Ethernet connector allows you to
connect to a computer or an Ethernet network.
Nitrogen Purge Port: Provides the connection to purge the instrument
with dry nitrogen in order to prevent condensation on the optical and measurement systems. For detailed information regarding the nitrogen purge
port, see “Dry Nitrogen Connection” on page 4-8.
2-4
Optilab rEX User’s Guide (M1500 Rev. D)
3
Quick Start
This chapter provides rudimentary setup procedures for first-time or experienced users who want to start the Optilab rEX installation process
before reading the entire manual.
Detailed descriptions and important use instructions concerning the
Optilab rEX are provided in the chapters that follow.
CONTENTS
PAGE
3.1 Setting Up the Optilab rEX ............................................................. 3-2
Optilab rEX User’s Guide (M1500 Rev. D)
3-1
Chapter 3: Quick Start
3.1 Setting Up the Optilab rEX
This section describes basic setup procedures for those who want to begin
using the Optilab rEX as soon as possible.
More details about setting up the Optilab rEX are provided in Chapter 4,
“Installation and Setup”. (You may notice that the setup sequence in this
chapter differs a bit from that in Chapter 4. The sequence in this chapter
allows you to begin stabilizing the temperature earlier in the sequence.)
See Chapter 2, “Instrument Description” for descriptions of the front and
rear panel controls and connections.
For instructions on navigating the LCD display tabs, see “Navigating the
Optilab rEX Tabs” on page 5-2.
Note:
The Optilab rEX can be safely stacked above and below other instruments.
1. Connect the power cable. The power outlet is located on the Optilab
rEX rear panel (see Figure 2-2). The power supply is universal, for
immediate use with 100–120 V or 220–240 V power at 50-60 Hz. (See
also “Power and Signal Connections” on page 4-2.)
2. Power ON the Optilab rEX. Time to full warm-up is approximately
30 minutes. (See also “Power On and Warm Up” on page 4-9.)
3. Set temperature. The Optilab rEX default temperature is 25°C, with
a range of 4°C to 50°C. (If you are operating below 25°C, it is important
that you see “Dry Nitrogen Connection” on page 4-8 before cooling the
instrument.)
4. Make fluid connections. Standard HPLC fittings: 1/16 in. OD tubing, 10-32 threads. The Optilab rEX should be connected last in line if
other detectors are to be connected in series. (See also “Fluid Connections” on page 4-7.) The IN and OUT ports are located behind a door on
the front panel (see Figure 2-1).
Tubing recommendations are:
•
0.010 in. (0.254 mm) ID to the Optilab rEX IN port.
•
0.020 in. (0.508 mm) or larger ID from the Optilab rEX OUT port
to a waste bottle or solvent recycle valve.
5. Flush the Optilab rEX in purge mode. Use 20 mL of co-miscible
solvents stepwise as necessary to prepare the cell for data collection.
(See also “Purging the Optilab rEX” on page 4-9.) Navigate to the
Purge On/Off button using the front panel arrow keys (see Figure 2-1).
3-2
Optilab rEX User’s Guide (M1500 Rev. D)
Setting Up the Optilab rEX
The Optilab rEX is shipped with Ethanol in the flow cell. A typical
series of solvents (from polar to nonpolar) is shown below. Salt solutions should be considered separate steps from pure solvents.
6. Zero the instrument. Activate the Zero selection on the Optilab rEX
LCD display. (See also “Main Tab” on page 5-3)
7. Install software.
a. For in-line use with chromatography, install ASTRA or equivalent
chromatography software. See the appropriate software manual
for installation instructions.
b. For off-line use (e.g., dn/dc determinations), install ASTRA V or
DNDC software. See the appropriate software manual for installation instructions.
8. Connect communication cable. (See also “Power and Signal Connections” on page 4-2.)
a. If data is to be collected using the ASTRA V software, connect the
Optilab rEX directly to a computer or local area network (LAN)
using the Ethernet cable provided.
b. If data is to be collected using ASTRA 4.X, DNDC, or other software, connect the Optilab rEX analog output to a DAWN or
miniDAWN instrument’s analog input AUX1 port using the analog
cable provided.
Optilab rEX User’s Guide (M1500 Rev. D)
3-3
Chapter 3: Quick Start
3-4
Optilab rEX User’s Guide (M1500 Rev. D)
4
Installation and Setup
This chapter describes the fluid, power, and signal connections used in
setting up the Optilab rEX.
CONTENTS
PAGE
4.1 Power and Signal Connections ...................................................... 4-2
4.1.1 Power Connector....................................................................... 4-2
4.1.2 Signal Connectors ..................................................................... 4-2
4.1.3 Communication Connector........................................................ 4-7
4.2 Fluid Connections........................................................................... 4-7
4.3 Dry Nitrogen Connection ................................................................ 4-8
4.4 Power On and Warm Up ................................................................ 4-9
4.5 Purging the Optilab rEX.................................................................. 4-9
4.6 Instrument Stability Check.............................................................. 4-10
Optilab rEX User’s Guide (M1500 Rev. D)
4-1
Chapter 4: Installation and Setup
4.1 Power and Signal Connections
All power and signal connections to the Optilab rEX are made using the
interfaces on the rear panel of the instrument. Refer to Figure 4-1 to view
the connectors on the rear panel of the Optilab rEX.
Figure 4-1: Rear panel power and signal connections
4.1.1 Power Connector
The power input accepts 100–250 VAC at 50–60 Hz. The power input
module contains two fuses, each rated at 2 Amps, one for the line voltage
in, and the other for the line voltage return.
4.1.2 Signal Connectors
The instrument rear panel contains 10 RJ-12 connectors for TTL inputs
and outputs, analog input and output, auto inject input and output, and a
solenoid drive output.
Cables not supplied by Wyatt Technology may use a different color code
scheme or have a different correspondence between color and pin number.
If you are using non-Wyatt Technology supplied cables, refer to Figure 4-2
and Table 4-1 to determine the correct pin number and wire usage. We
recommend using only cables supplied by Wyatt Technology; wiring the
connection incorrectly could damage your instrument.
Pinouts for the RJ-12 connectors used in Wyatt Technology-supplied
cables are shown in Figure 4-2.
4-2
Optilab rEX User’s Guide (M1500 Rev. D)
Power and Signal Connections
Pin
Wire Color
1
White
2
Black
3
Red
4
Green
5
Yellow
6
Blue
Figure 4-2: RJ-12 Connector and Pinouts
Several general-purpose cables are supplied for TTL inputs and outputs,
analog inputs and outputs, auto inject input and output, and solenoid
drive output.
Earlier revisions of the general-purpose cables have different wire colors
than those listed in Figure 4-2. If your Wyatt Technology supplied generalpurpose cables do not have the same colors listed in Figure 4-2, refer to the
wire colors listed in Appendix D, “Wire Colors”.
Figure 4-3: General-purpose cable
An analog out cable is supplied to connect to the Optilab rEX analog
output to a DAWN or miniDAWN AUX analog input.
Optilab rEX User’s Guide (M1500 Rev. D)
4-3
Chapter 4: Installation and Setup
Figure 4-4: Analog Optilab rEX to DAWN or miniDAWN cable
When you connect your Optilab rEX to other instruments, see Table 4-1
for RJ-12 connector signal information.
Table 4-1: RJ-12 Signal Function
Optilab rEX
Connector
RJ-12 Connector Wire Signal
White
Black
Red
Green
Zero In
Signal
Signal
Ground
Purge In
Signal
Signal
Ground
Recycle In
Signal
Signal
Ground
Alarm In
Signal
Signal
Ground
Auto Inject In
Signal
Signal
Ground
Analog In
Positive
Negative
Analog Out
Positive
Negative
Recycle Out
Signal
Signal
Ground
Alarm Out
Signal
Signal
Ground
Auto Inject Out
Contact
Contact
Yellow
Blue
Ground
Ground
The Zero In, Purge In, Recycle In, Alarm In, and Alarm Out signals all
follow the TTL voltage convention. In the TTL convention, 5 V on the
signal line is interpreted as a High signal, and 0 V on the signal line is
interpreted as a Low signal. Input signals to the Optilab rEX must have a
duration of at least 100 msec in order to be reliably detected.
4-4
Optilab rEX User’s Guide (M1500 Rev. D)
Power and Signal Connections
Zero In: TTL input on red (signal) and green (signal ground). When the
signal on this line transitions from 0 V to 5 V, the last measured value of
dRI is considered to be zero value, and is subtracted from the dRI data
before it is output. This is exactly equivalent to activating the Zero button
on the LCD display Main tab.
Purge In: TTL input on red (signal) and green (signal ground). When the
signal on this line transitions from 0 V to 5 V, the internal purge valve is
actuated, purging the reference chamber. While the signal on this line is
held at 5 V, the purge valve remains actuated. When the signal on this
line transitions from 5 V to 0 V, the purge valve is de-actuated. This is
exactly equivalent to activating the Purge button on the LCD display
Main tab (see “Main Tab” on page 5-3).
Recycle In: TTL input on red (signal) and green (signal ground). When
the signal on this line transitions from 0 V to 5 V, the instrument actuates
an external solenoid valve by supplying power to the Recycle Out
connector.
Alarm In: TTL input on red (signal) and green (signal ground). On the
instrument LCD display Alarms tab (see “Alarms Tab” on page 5-5), you
may select the active state of this input. If you select “Active High”, the
instrument considers a transition on this line from 0 V to 5 V to be an
Alarm In event. If you select “Active Low”, the instrument considers an
Alarm In event to occur when the signal on this line transitions from 5 V
to 0 V. When an Alarm In event occurs, the Alarm signal flashes on the
LCD display, and an Alarm Out signal is transmitted (see Alarm Out).
Auto Inject In: TTL input or contact closure input between wires red
(TTL signal) and green (TTL signal ground). The red signal line is internally held at 5 V. When the red signal line is brought to 0 V, the
instrument receives an Auto Inject signal. The signal line may be brought
to 0 V by simply connecting the red and green wires together (hence the
term contact closure). Most auto injectors supply a contact closure signal,
which simply brings the two wires into contact with each other.
In general, the same auto injector contact closure signal cannot be sent to
multiple instruments, since different instruments may be trying to
maintain different internal voltages to sense the contact closure, and the
instruments could be in conflict with each other.
The Optilab rEX provides an Auto Inject Out signal that simply retransmits the Auto Inject In signal as a contact closure output (see Auto Inject
Out), allowing you to bring an auto injector contact closure signal to the
Optilab rEX, and then send the signal to another device. The receipt of
this signal by the Optilab rEX causes a mark to appear in the data on the
LCD display Main tab, changes the state reported on the LCD display
System tab Auto Inject input field, and causes a signal to be sent with the
digital data stream indicating the time of receipt of the signal.
Optilab rEX User’s Guide (M1500 Rev. D)
4-5
Chapter 4: Installation and Setup
Analog In: Analog input Positive on red, Negative on green, and Ground
on blue. The Optilab rEX digitizes an analog input in the range of ±10 V
with a resolution of 0.31 mV (16 bits).
Analog Out: Analog output Positive on white, Negative on black, and
Ground on blue. The Optilab rEX supplies an analog output in the range
of ±10 V with a resolution of 0.31 mV (16 bits). On the LCD display System>Constants dialog, you may set the instrument to use only a subset of
the possible voltage range (i.e., –1 V to +1 V), but the minimum voltage
step remains at 0.31 mV. In the same dialog, you may set the dRI range to
be presented over that voltage range, which determines the analog out calibration constant in Refractive Index Units (RIU)/Volt.
Recycle Out: The solenoid valve drives current on the white and black
wires (the current direction is irrelevant for the solenoid). This signal may
be connected to a user-supplied solenoid valve or a Wyatt Technology
Recycle unit, which contains an internal solenoid valve that switches
between waste and recycle. When this connector is actuated (via the
System tab or the Recycle In input), the connector supplies current to
drive a 12 V solenoid valve. The valve is actuated with 12 V (up to 1 Amp,
depending upon resistance of the solenoid), held for 0.1 second, and then
dropped down with 12 V across an internal 51 Ohm resistor.
Alarm Out: TTL output on white (signal) and black (signal ground). On
the instrument LCD display Alarms tab (see “Alarms Tab” on page 5-5),
you may select the active state of this output. If “Active High” is selected,
the instrument keeps this signal at 0 V for no alarm state, and brings the
signal to 5 V in the event of an alarm state. If “Active Low” is selected, the
instrument keeps this signal at 5 V for no alarm state, and brings the
signal to 0 V in the event of an alarm state. In this context, an alarm state
occurs if the internal liquid leak sensor detects liquid, or the internal
vapor alarm detects organic solvent vapors, or the rear panel connector
Alarm In signal is active (see Alarm In).
Auto Inject Out: Contact closure output between wires white and black.
This signal is a retransmit of Auto Inject In (see Auto Inject In). Internal
to the instrument, the white and black wires are normally not in contact
with one another. Upon actuation of this contact closure retransmit, the
white and black wires are brought into contact with each other inside the
instrument.
4-6
Optilab rEX User’s Guide (M1500 Rev. D)
Fluid Connections
4.1.3 Communication Connector
The rear panel has one Ethernet connector, allowing digital communication to an external computer.
Ethernet: Standard Ethernet cable for connecting the instrument to an
Ethernet network, see Figure 4-5.
Figure 4-5: Ethernet cable
Detailed instrument digital connectivity instructions are given in
Appendix E, “Instrument Connectivity”.
4.2 Fluid Connections
The tubing recommendations for the Optilab rEX are:
•
•
0.010 in. (0.254 mm) ID to the Optilab rEX inlet
0.020 in. (0.508 mm) or larger ID from the Optilab rEX outlet to a
waste bottle or solvent recycle valve.
The Optilab rEX accepts standard HPLC fittings: 1/16 in. outer diameter
tubing with 10-32 threads.
Note:
The Optilab rEX should be connected last in line if other detectors are connected in series.
The reasons for connecting the Optilab rEX last in line are:
•
The seals on the quartz flow cell inside the Optilab rEX can withstand
fluid pressures up to 100 psi (7 bar). However, the solenoid valve
inside the Optilab rEX will no longer function properly, and may leak,
with fluid pressures above 30 psi (2 bar). The back pressure generated
by some instruments can exceed 30 psi or even 100 psi with only
moderate flow rates, and so the Optilab rEX may be damaged if it is
placed upstream of another instrument.
•
Pressure fluctuations, such as result from pump pulses, cause measurable changes in a fluid’s refractive index. With the Optilab rEX
plumbed upstream of another detector, any pump pressure pulses are
magnified due to the backpressure from the downstream instrument,
causing a larger pump pulse signal in the data stream from the
Optilab rEX.
Optilab rEX User’s Guide (M1500 Rev. D)
4-7
Chapter 4: Installation and Setup
•
The Optilab rEX contains internally 0.010 in. (0.254 mm) ID stainless
steel tubing from the IN port to the input to the flow cell, and 0.030 in.
(0.762 mm) ID from the outlet from the flow cell to the OUT port. The
large diameter tubing from the flow cell to the OUT port is intended to
give the best possible pressure reference to atmospheric pressure for
the reasons discussed in Item 2 above. However, large diameter tubing
causes a great deal of mixing of the sample, resulting in band broadening for any instrument placed downstream of the Optilab rEX. Large
ID outlet tubing does not effect the broadening between an instrument
upstream of the Optilab rEX and the Optilab rEX itself.
4.3 Dry Nitrogen Connection
When operating below ambient temperature, a dry nitrogen purge is
essential to prevent condensation on the optical and measurement
systems.
To prevent condensation, attach a dry air or nitrogen line to the Nitrogen
Purge fitting on the rear panel of the Optilab rEX (see Figure 2-2). Use a
right-angle male connector and a 10-foot length of Polyethylene tubing,
provided with the Optilab rEX, to connect to the Nitrogen Purge fitting.
The pressure in the dry air or nitrogen line should be 20–80 psi
(0.14–0.28 MPa). With a pressure of 25 psi, the dry gas flows into the temperature regulated box at a rate of approximately 38 mL/minute. A
standard high pressure gas tank contains about 8,600 L of gas at STP, and
so a tank should supply a single Optilab rEX for approximately 150 days.
The Optilab rEX has an internal pressure sensor that measures the
pressure of the dry gas being supplied. The measured dry gas pressure
may be viewed on the LCD display Alarms tab. If the dry gas pressure
drops below 20 psi (0.14 MPa), then the temperature control set point
cannot be set below 20.5°C. If the system temperature is set below 20°C
and the dry gas pressure subsequently drops below 20 psi (for example, if
a nitrogen tank is fully depleted), the temperature control set point is
automatically changed to 20.5°C.
4-8
Optilab rEX User’s Guide (M1500 Rev. D)
Power On and Warm Up
4.4 Power On and Warm Up
The power switch for the Optilab rEX is located on the front of the instrument in the lower right hand corner (see Figure 2-1). Start by powering on
the instrument using this switch.
After powering on, set the temperature control set point from the LCD
display Main tab as described in “Main Tab” on page 5-3. The Optilab rEX
has a temperature range from 4°C to 50°C. Subambient temperature operations require the flow of dry gas into the temperature controlled
environment, as described in “Dry Nitrogen Connection” on page 4-8.
After setting the temperature control set point, wait approximately
30 minutes for the instrument to stabilize. If the temperature set point is
quite different from room temperature, the instrument stability continues
to improve for several hours. Flushing the instrument, as described in
“Purging the Optilab rEX” on page 4-9, may be performed during this
warm up period.
If the LCD display hangs (freezes) or crashes, see “Microsoft Windows
Encounters Problems” on page 9-4 for information about rebooting.
4.5 Purging the Optilab rEX
Navigate to the PURGE button on the Main tab of the LCD display, and
enable the purge valve. If the purge valve is enabled, the button is yellow
and reads “Purge On”. If the purge valve is disabled, the button is green in
color and reads “Purge Off”.
With the purge valve disabled, liquid flows from the IN port, through the
flow cell sample chamber, and then through the OUT port, bypassing the
flow cell reference chamber. If the purge valve is enabled, then liquid flows
from the IN port, through the flow cell sample chamber, through the flow
cell reference chamber, and finally to the OUT port, flushing liquid
through both the sample and reference chambers. Flush the Optilab rEX
in purge mode with 20 mL of co-miscible solvents stepwise as necessary to
prepare the cell for data collection. The Optilab rEX is shipped with
Ethanol in the flow cell. A typical series of solvents (from polar to nonpolar) is shown below.
Note:
Salt solutions should be considered separate steps from pure solvents.
Optilab rEX User’s Guide (M1500 Rev. D)
4-9
Chapter 4: Installation and Setup
When the solvent required for data collection has been thoroughly flushed
through both the sample and reference chambers, disable the purge valve.
The fluid in the reference chamber is now captive, and the refractive index
difference between this captive reference fluid and the fluid stream
directed through the sample chamber is reported as the differential refractive index (dRI). Navigate to the Zero button on the LCD display Main tab,
and press Enter to cause the current state to be considered the “zero” differential refractive index.
4.6 Instrument Stability Check
To perform an instrument stability check, do the following:
1. Purge the Optilab rEX as described in “Purging the Optilab rEX” on
page 4-9.
2. Un-plumb the instrument from any fluid lines.
3. Insert a plug (shipped with the Optilab rEX) into the OUT port (see
Figure 2-1) and leave the IN port open to the atmosphere.
4. From the LCD display Main tab, set the temperature set point to 25°C
and wait approximately 30 minutes for the instrument to stabilize.
The instrument stability continues to improve for several hours after
the temperature set point has been changed.
5. Navigate to the LCD display System tab, press ENTER on the Constants button, and set the Collection interval to 2.0 seconds (equivalent to a 4 second time constant).
6. Navigate back to the LCD display Main tab and select View: dRI.
7. Observe the dRI signal through time.
Short term noise should be seen to be less than ±2 x 10-9 RIU, when
measured as per ASTM-E1303-95 (2000) using a 2 second Collection
interval (equivalent to a 4 second time constant).
4-10
Optilab rEX User’s Guide (M1500 Rev. D)
5
Using the LCD Display
This section describes the keypad controls and the tabbed interface on the
LCD display on the front panel of the instrument. These tabs allow you to
monitor, configure, and control the function and operation of the Optilab
rEX.
CONTENTS
PAGE
5.1 Navigating the Optilab rEX Tabs..................................................... 5-2
5.2 Main Tab ......................................................................................... 5-3
5.3 aRI Tab ........................................................................................... 5-4
5.4 Alarms Tab...................................................................................... 5-5
5.5 System Tab..................................................................................... 5-7
5.5.2 LED Intensity Dialog.................................................................. 5-11
5.5.1 Constants Dialog ....................................................................... 5-9
5.6 Communications Tab ...................................................................... 5-13
Optilab rEX User’s Guide (M1500 Rev. D)
5-1
Chapter 5: Using the LCD Display
5.1 Navigating the Optilab rEX Tabs
The keypad consists of a number, TAB, ESC, DEL,
ENTER, and arrow keys.
You use these keys to move through the tabs on the
LCD display on the instrument front panel and to
enter values where applicable.
To select a tab on the LCD display:
1. Press the TAB key until the cursor is positioned
on a tab title at the top of the screen
2. Use an arrow key to move to the desired tab.
Each tab is displayed as you use arrow keys to
move to another tab.
Once the desired tab is displayed, use the keys as
follows:
Note:
•
•
•
TAB key: Move forward to the next field within a tab.
•
ENTER key: Save an entry made using the number buttons, “click” a
button, select an option, or choose an item in a pull-down list.
•
Up and Down Arrow keys: Move to a different selection within a
pull-down list or radio field.
•
Right and Left Arrow keys: Move to another tab, or move the cursor
within a numeric field.
ESC key: Exit a pull-down list or to cancel an entry.
DEL key: Remove the previous character from a numeric entry field.
(Same as Backspace on a regular keyboard.)
The TAB key only moves in the forward direction.
The sections that follow describe the Optilab rEX LCD display tabs.
5-2
Optilab rEX User’s Guide (M1500 Rev. D)
Main Tab
5.2 Main Tab
The Main tab allows you to view either the dRI or the instrument temperature through time.
Figure 5-1: Main tab
View: Viewing options are either dRI or temperature. If you select dRI,
the dRI data is shown over a period of time. If you select temperature, the
temperature data is shown over a period of time.
x-axis: Selects the length of time to be displayed on the screen on the xaxis.
y-axis: Options are Auto or Manual. Auto automatically determines the
range to display on the y-axis. To customize the y-axis, select Manual, tab
to the Change y-axis button and press ENTER. Enter the desired numeric
values using the keypad in the pop-up dialog that appears on the screen,
navigate to the OK button, and press ENTER.
Temperature (°°C) Set: Enter the value for the temperature that the
instrument is to maintain. The value shown in the box to the right
displays the current internal temperature of the instrument. The box
displays as yellow until the temperature stabilizes. When the temperature
has remained within ±0.05°C of the Temperature (°C) Set value for a
minimum period of 15 minutes, the box is green.
Optilab rEX User’s Guide (M1500 Rev. D)
5-3
Chapter 5: Using the LCD Display
Alarm: Flashes red if an instrument alarm is active, and remains solid
green if no alarms are active. If any of the alarm conditions are detected,
the Alarm button flashes on the Main tab, the aRI tab, and the Alarms
tab. Navigate to the Alarms tab to determine the nature of the alarm.
Purge Off: This is a toggle button that turns the purge valve On or Off. In
the ON state, the purge valve purges the reference chamber. If the purge
valve is OFF, then fluid flows from the IN port, through the flow cell
sample chamber, and then through the OUT port. If the purge valve is
ON, then fluid flows from the IN port, through the flow cell sample
chamber, through the flow cell reference chamber, and finally to the OUT
port.
Zero: Press ENTER on this button to cause the current value of dRI to be
considered “zero” value.
5.3 aRI Tab
The aRI tab is used to view the aRI value of the solvent in the flow cell.
Figure 5-2: aRI tab
In order to measure the aRI, the same liquid must be present in both the
sample and reference chambers. The purge valve should be ON and both
chambers should be carefully flushed with the liquid to be measured.
RIU: With the purge valve ON, displays the aRI of the liquid in the flow
cell.
5-4
Optilab rEX User’s Guide (M1500 Rev. D)
Alarms Tab
5.4 Alarms Tab
The Alarms tab allows you to view the current state of Optilab rEX
alarms, and to set the voltage state of external alarms. If any alarm is
detected, the Alarm button flashes on the Main, aRI, and Alarms tabs.
If no alarm conditions are detected, the status buttons display a green OK.
If an alarm condition is detected, the status buttons display a flashing red
Alarm.
Figure 5-3: Alarms tab
External alarm settings are used when alarms from additional instruments or systems are daisy chained through the Optilab rEX. Connections
are made at the rear panel using the Alarm In or Alarm Out connectors.
External alarm IN: The External alarm IN is an input used to capture
alarms from additional devices, and then retransmit that alarm as an
External alarm OUT.
For example, multiple instruments in a chromatographic system typically
have liquid leak detectors. It is desirable that the solvent pump be shut off
in the event of a liquid leak in any one of those instruments. Since the
alarm outputs from each instrument cannot all be connected to the same
pump shut-off signal line, the alarm outputs from the instruments need to
Optilab rEX User’s Guide (M1500 Rev. D)
5-5
Chapter 5: Using the LCD Display
be logically ORed with each other. The External alarm IN is logically
ORed with the Optilab rEX internal vapor and liquid leak alarms, and
then retransmitted as the External alarm OUT.
Different devices have different conventions for alarm states. Some
maintain a 5 V state on a wire to indicate no alarm, and bring the voltage
to 0 V to indicate an alarm condition. This is called the “Active Low” convention. Others use 5 V to indicate an alarm condition; this is the “Active
High” convention.
Select High or Low depending on the voltage output convention of the connecting device. If the connecting device expects to receive a low voltage to
signal an alarm, select Low. Voltage signal ranges are from 0 V to 5 V.
External alarm OUT: This output signal is the logical OR of the
External alarm IN, the Vapor alarm, and the Liquid leak alarm. If connecting a device to the Optilab rEX External alarm OUT, select High or
Low depending on the voltage input of the external device. If the connecting device expects to receive a low voltage to signal an alarm, select Low.
Voltage signal ranges are from 0 V to 5 V.
Nitrogen pressure: Displays the gas pressure in psi of the gas line
attached to the back panel nitrogen purge port (see Figure 2-2). For subambient operation, this pressure must be greater than 20 psi.
Temperature: Displays the current temperature in degrees Centigrade
(°C) inside the Optilab rEX.
Alarm status area: This area displays red for the following items if an
alarm is active. Otherwise, it shows green for each item.
5-6
•
Vapor alarm: Displays an alarm indication when organic solvent
vapors are present in the instrument chassis.
•
Liquid leak alarm: Displays an alarm indication if the sensor located
inside of the Optilab rEX comes in contact with any liquids.
•
Overheated (temperature > 65°°C): Displays an alarm indication if
the temperature rises above 65°C. If this condition occurs, the
heater/cooler is disabled and cannot be re-enabled until the power to
the instrument has been cycled off and then on.
•
Nitrogen pressure: Displays an alarm indication when the temperature drops below 20°C and the nitrogen pressure drops below 20 psi
(0.14 MPa).
•
External alarm IN: Displays an alarm indication if the instrument
detects a voltage signal on the rear panel Alarm In connector from an
external device as configured by the External alarm IN Active High or
Low button.
•
External alarm OUT: Displays an alarm indication if the instrument
is sending an alarm out through the rear panel Alarm Out connector.
The voltage state of the External alarm OUT signal is configured by
the External alarm OUT Active High or Low button.
Optilab rEX User’s Guide (M1500 Rev. D)
System Tab
•
Low light: Displays an alarm indication if sufficient light is not being
transmitted through the flow cell. Possible causes are bubbles in the
flow cell, extreme refractive index differences between the sample and
reference cells (as occurs when switching solvents or when the sample
concentration is well beyond the instrument’s maximum range), or a
faulty light source. See “Low Light Alarm” on page 9-2 and “LED
Intensity Dialog” on page 5-11.
Audio Alarm On/Off: Navigate to this button and press ENTER to toggle
the Audio Alarm On or Off.
Help: This button displays the Help information for this tab.
5.5 System Tab
The System tab allows you to configure a waste or recycle activation, set
the time of day and the wavelength of the LED/fiber light source, view the
instrument’s serial number and the Auto Inject input status, turn the
LED/fiber light source on or off, and modify calibration constants and
analog out parameters.
Figure 5-4: System tab
Optilab rEX User’s Guide (M1500 Rev. D)
5-7
Chapter 5: Using the LCD Display
Waste/Recycle: Modifies the state of the external solenoid valve output
signal on the rear panel Recycle Out connector. Possible choices are Immediate activation or Delayed activation. If Delayed activation is selected,
enter the number of minutes to delay activation in the Time delay field.
The ON or OFF box indicates activation status. If an activation is pending,
the status box indicates PENDING, and a countdown below the box shows
the time left before activation.
Activate: Press ENTER on this button to enable an external Waste/Recycle solenoid valve. If the Delayed activation choice is selected, the solenoid
valve actuates after the specified time delay.
Auto Inject input: Displays the status of the signal presented to the rear
panel Auto Inject In connector. The Auto Inject In is a contact closure
signal, which may be Open, indicating no contact between the signal
wires, or Closed, indicating that the signal wires are physically connected.
Zero upon Auto Inject: When this item is selected and an Auto Inject
signal is received, the last measured value of dRI is considered to be a zero
value. That value is subtracted from the dRI data before it is output.
Time: Displays the current time of day used by the instrument. To change
the time of day, navigate to the Change button and enter the new values.
Wavelength (nm): Displays the current value of the wavelength of the
LED/fiber light source, which is stored in the instrument’s onboard
memory. This value should not be changed while a light source is connected. See “Changing the Wavelength Setting” on page 8-9 for
instructions regarding changing the wavelength.
CAUTION: Changing the wavelength value can change the current sent to the light
source, and it is possible to destroy a light source if the wavelength is
changed while the light source is connected.
To change the wavelength value, navigate to the Change button. Enter the
value that comes with that light source. Changing the wavelength value
does not physically alter the wavelength of light used by the instrument.
Serial number: Displays the serial number of the instrument.
Software version: Displays the version number of the firmware running
on the Optilab rEX. After a firmware upgrade, you must use the Restart
button to restart the instrument.
Constants…: Refer to “Constants Dialog” on page 5-9.
LED…: Refer to “LED Intensity Dialog” on page 5-11.
5-8
Optilab rEX User’s Guide (M1500 Rev. D)
System Tab
5.5.1 Constants Dialog
The Constants dialog opens if you select the Constants button in the
System tab.
The Constants dialog allows you to set the calibration values used by the
Optilab rEX. These values should be set before operating the instrument,
and should be periodically checked for accuracy by running known
samples.
Note:
To change the + and – signs, tab to the box that contains the sign value
and press the ENTER key to toggle between the + and – values.
System Constants: Values of various instrument calibration constants
and measurement time constant.
•
dRI calibration constant: Relates light beam movement to the
dRI.
•
dRI offset: Determines the light beam position that corresponds
to zero dRI.
•
aRI calibration constant: Relates light beam movement to aRI.
•
aRI offset: A second calibration constant associated with aRI.
Optilab rEX User’s Guide (M1500 Rev. D)
5-9
Chapter 5: Using the LCD Display
•
Collection interval: The time in seconds between data slices sent
as a digital output. The minimum collection interval is 0.105 seconds, and the maximum is 2.53 seconds. The time over which data
is averaged (the measurement time constant) is automatically set
to be 2x the collection interval.
dRI analog out range: The voltage output presented on the rear panel
Analog Out connector may be adjusted by setting this parameter to
Narrow, Standard, Wide, Full, or Manual. Table 5-1 describes the values
set by these parameters.
Table 5-1: dRI Analog Out Range Settings
dRI Analog
Out Range
Setting
Min
Max
Min
Max
dRI Analog Out
Calibration Constant
(RIU/V)
Narrow
-10
+10
-2x10-5
+2x10-5
2x10-6
Standard
-10
+10
-2x10-4
+2x10-4
2x10-5
Wide
-10
+10
-1x10-3
+1x10-3
1x10-4
Full
-10
+10
-4.7x10-3
+4.7x10-3
4.7x10-4
Manual
User defined User defined User defined User defined defined by user
selected values
Note:
Voltage (V)
dRI (RIU)
The instrument’s dynamic range exceeds 21 bits of resolution (more than
2 x 106 discreet steps). The 21-bit full range and sensitivity may be simultaneously accessed only via digital communication. The Digital/Analog
converter has 16 bits of resolution (65,535 discreet steps) between –10 V
and +10 V. If the entire dRI range is selected for analog output, the
smallest observable signal on the analog output is set by the 16 bit Digital/Analog resolution, effectively reducing sensitivity. You may select any
subset of the instrument range to be output within ±10 V.
•
dRI analog out calibration constant: Relates the dRI change to
voltage presented on the analog out signal. The dRI analog out calibration constant is calculated as:
( dRIMAX - dRIMIN ) / ( VoltageMAX - VoltageMIN )
If you set the dRI analog out range parameter to Narrow, Standard, Wide, or Full, the Min and Max output Voltages and dRI values are set to preset values as in Table 5-1.
If you set the dRI analog out range parameter to Manual, you may
set the Min and Max output Voltages to any value between -10 V
and +10 V. You may also set the Min and Max dRI values to any
value.
If you set the dRI analog out range parameter to Standard, the
voltage response from a BSA solution (dn/dc at 690 nm = 0.185
RIU/g/mL) of concentration 1 mg/mL in the flow cell will remain
barely below 10 V.
5-10
Optilab rEX User’s Guide (M1500 Rev. D)
System Tab
Restore Factory Defaults: Navigate to Set to Defaults to return all
system values to their factory default settings.
Apply: Navigate to Apply to save changes made in this dialog.
Close: Navigate to Close or press the ESC key to return to the System tab.
5.5.2 LED Intensity Dialog
The LED Intensity dialog opens if you select the LED button in the
System tab.
The LED Intensity dialog allows you to turn off the LED/fiber light source
in order to prolong the life of the light source. This tab also allows you to
set the amount to power that goes to the light source and thus the light
intensity.
ON or OFF: Turn the power to the LED/fiber light source on or off.
Optimize: Auto determine the optimal Percent max power to send to the
LED/fiber light source. Sets the LED power to bring the Light Intensity to
an optimal value. For 660 or 690 nm light sources, that optimal value is
7.8 V. Table 5-2 shows optimal voltage values for LED/fiber light sources
with other wavelengths. See “Optimizing the LED/Fiber Light Source” on
page 8-10 for instructions regarding this button.
Percentage of max power: Sets the power to the LED/fiber light source.
See “Setting the Percent Max Power to Zero” on page 8-2 for instructions
regarding setting this field to 0% when changing the light source.
Optilab rEX User’s Guide (M1500 Rev. D)
5-11
Chapter 5: Using the LCD Display
Light Intensity: Displays the current signal in Volts from the photodetector, which is proportional to the intensity of light detected by the
photodetector. For optimal performance, this value should be near 7.8 V
for 660 or 690 nm light sources. The LED optimal and threshold voltages
for LED/fiber light sources are as follows.
Table 5-2: LED Optimal Intensity and Low Light Thresholds
Wavelength (λ
λ)
Range (nm)
Optimal LED
Intensity (V)
LED Intensity Low
Light Threshold (V)
λ < 568
6.2
4
568 ≤ λ < 725
7.8
5
725* ≤ λ
7.8
5
* Theoretical values. Please contact Wyatt Technology Corporation for
current information concerning wavelengths greater than 725 nm.
The photodetector saturates slightly above 8 V, at which point an increase
in light intensity no longer results in an increase in the signal voltage
from the photodetector. Instrument performance degrades significantly if
the photodetector voltage is above 8 V, and very slightly as the photodetector signal drops below the optimal value. When this voltage drops below 5
V for 660 or 690 nm light sources, a Low Light Alarm is activated. See
“Low Light Alarm” on page 9-2.
Close: Navigate to Close or press the ESC key to return to the System tab.
5-12
Optilab rEX User’s Guide (M1500 Rev. D)
Communications Tab
5.6 Communications Tab
The Communications tab allows you to set parameters regarding communication with computers. The Optilab rEX is equipped for Ethernet
communication. Ethernet communication allows the instrument to be presented to any computer on a local area network.
See Appendix E, “Instrument Connectivity” for instructions regarding
network communications setup.
Figure 5-5: Communications tab
DHCP/Static IP: Select DHCP to have the Ethernet network automatically assign an IP address to the instrument. Select Static IP to manually
assign a fixed IP address and subnet mask.
IP Address / Subnet Mask: If you select DHCP, these fields display your
automatically assigned IP Address and Subnet Mask values. If you select
Static IP, enter the IP Address and Subnet Mask values. Contact your
network administrator for valid static IP Address and Subnet Mask
values.
Instrument Name: Shows the instrument name used on an Ethernet
network.
Optilab rEX User’s Guide (M1500 Rev. D)
5-13
Chapter 5: Using the LCD Display
5-14
Optilab rEX User’s Guide (M1500 Rev. D)
6
Off-Line Measurements
This chapter provides general information for instrument calibration,
sample preparation, dn/dc measurement, and aRI measurement.
CONTENTS
PAGE
6.1 Instrument Calibration .................................................................... 6-2
6.1.1 General Information and Sample Preparation........................... 6-2
6.1.2 HPLC Pump with Injector .......................................................... 6-3
6.1.3 Syringe Pump Infusion .............................................................. 6-3
6.1.4 Collecting Data .......................................................................... 6-4
6.2 dn/dc Measurement........................................................................ 6-4
6.3 Absolute Refractive Index Measurement........................................ 6-5
Optilab rEX User’s Guide (M1500 Rev. D)
6-1
Chapter 6: Off-Line Measurements
6.1 Instrument Calibration
The Optilab rEX can be calibrated as described in this section.
6.1.1 General Information and Sample Preparation
For off-line operation, the Optilab rEX’s performance should be checked
regularly against a standard with a known dn/dc value. The dn/dc (mL/g)
value is the change in solution refractive index with a change in solute
concentration. For use with a chromatography system and the ASTRA
software, this check may be performed by injecting a standard sample and
verifying that the injected and calculated masses are equal.
The calibration may be performed using any material of known dn/dc. A
recommended standard is anhydrous sodium chloride dissolved in water,
which has a dn/dc of 0.172 mL/g at a wavelength of 690 nm (0.181 mL/g at
488 nm, 0.174 mL/g at 633 nm).
Appropriate concentrations should be mixed using clean distilled water in
clean glass containers. The highest concentration should be about 29 mg/
mL. Use six (or more) concentrations prepared to within 1% or better
accuracy to increase the precision of the final determination.
To successfully prepare samples, only use glassware that has been thoroughly and recently cleaned with pure, de-ionized water. Unclean
glassware or detergent residues will dramatically affect the measurement.
Glassware must be rinsed thoroughly, first with deionized water and then
with HPLC grade ethanol, methanol, or acetone. Then it must be air-dried
upside down on lint-free tissue. This applies to all flasks, vials, syringes,
etc., used during sample preparation.
Since your sample solvent may differ slightly from the solvent you are
using to flow through your Optilab rEX, you should be certain to prepare
“blanks,” which you will inject into your instrument at the beginning and
end of your collection run, allowing you to set a proper baseline.
The Optilab rEX can easily distinguish between solvent that has been
open to the air overnight and solvent fresh from a bottle. A concentration
change on the order of 1 ppm is detectable. Therefore, the samples and
blanks should be created from the same batch of solvent. For example: fill
a 250 mL flask with your HPLC grade water and use this water to make
your solutions and blanks.
After making your solutions, fill two or three extra containers with water
from the flask to act as blanks. Inject the blanks before your first concentration and after your last concentration. When you analyze your data,
draw a baseline from the blank injection at the beginning of the run to the
blank injection at the end of the run.
6-2
Optilab rEX User’s Guide (M1500 Rev. D)
Instrument Calibration
Samples should be kept well sealed to avoid evaporation. Some solvents
(such as water) keep fairly well for a number of months, but concentration
changes may occur over time due to evaporation or contamination.
6.1.2 HPLC Pump with Injector
This arrangement is shown in Figure 6-1. Use 0.01 in. ID tubing between
the injector and the Optilab rEX, and 0.02 in. ID tubing elsewhere. A flow
rate of 0.5–1.0 mL/minute is ideal. Use a large sample loop, 0.5–1.0 mL to
ensure that each injection produces a clear plateau and not a peak as it
passes through the Optilab rEX.
RI
detector
HPLC pump
Injector w/
loop
waste flask
Figure 6-1: Setting up an HPLC pump and injector for calibration
The objective is to inject known concentrations into the detector. If a peak
with a rounded top and no clear plateau is obtained, the concentration at
the top of the peak will be unknown; flat-topped plateaus indicate that the
cell has been fully flushed with sample solution.
A syringe pump fitted with a large syringe may be used instead of the
HPLC pump.
6.1.3 Syringe Pump Infusion
Another option is to connect the Optilab rEX as shown in Figure 6-2, using
a syringe pump. Use 0.02 in. ID tubing for both connections. A recommended flow rate is 0.1–0.2 mL/minute. The syringe must be rinsed and
dried thoroughly or replaced between samples to avoid contamination of
one concentration by the next sample. When the syringe is disconnected to
change samples, the pressure change and injected air may cause an
unstable baseline for several minutes.
PEEK tubing
syringe
syringe pump
RI
detector
waste flask
Figure 6-2: Setting up a syringe pump for calibration.
Optilab rEX User’s Guide (M1500 Rev. D)
6-3
Chapter 6: Off-Line Measurements
6.1.4 Collecting Data
The sample and reference cells should be flushed with pure solvent for
several minutes before making measurements. Press ENTER on the
Purge button on the Main tab, wait until the baseline is stable, then press
ENTER on the Purge button a second time. Monitor the baseline for a few
minutes to ensure that the baseline is still stable. Finally, zero the Optilab
rEX by pressing ENTER on the Zero button on the Main tab. After you
zero the Optilab rEX, it is ready to collect data.
Collect data using ASTRA V software, or via an analog connection to a
DAWN or miniDAWN instrument using DNDC software. One sample
solution is introduced at a time, beginning with the lowest concentration.
Wait for the signal to stabilize, which takes several minutes while the
previous solution gets completely rinsed out of the cell.
Each solution yields a plateau on the screen. After all of the concentrations have been measured, introduce solvent again and confirm that there
was little or no baseline drift during the measurement.
Refer to the ASTRA or DNDC User’s Guide for further information on how
to calculate the calibration constant.
6.2 dn/dc Measurement
Once you have collected data (i.e., dRI or output voltage vs. concentration),
it is possible to calculate either the calibration constant (if dn/dc is
known) or dn/dc (if the calibration constant is known). To measure dn/dc
values in solvents other than water, the solvents must be changed according to instructions in “Purging the Optilab rEX” on page 4-9.
It is extremely important that no residues from the old solvent are left in
either the reference cell or the flow cell compartment. Using another
solvent does not change the Optilab rEX calibration constant. The concentration range for the samples will vary depending on the dn/dc value of
each sample in the particular solvent.
6-4
Optilab rEX User’s Guide (M1500 Rev. D)
Absolute Refractive Index Measurement
6.3 Absolute Refractive Index Measurement
The Optilab rEX measures the absolute refractive index (aRI) of a fluid if
that fluid is present in both the sample and reference chambers. To
measure the aRI of a fluid, purge the system with the fluid to be measured
as described in “Purging the Optilab rEX” on page 4-9. As described in
that section, when switching between non-miscible fluids take care to
purge using one or several intermediate fluids. When the fluid to be
measured is present in both the sample and reference chambers, navigate
to the LCD display aRI tab, and activate the purge valve. With the purge
valve activated, the aRI of the fluid is displayed.
If there is a small refractive index difference between the fluids in the
sample and reference chambers, the aRI reported by the Optilab rEX is
not accurate.
See Appendix B, “Operating Principles and Theory” for a brief description
of the physics behind the Optilab rEX aRI measurement.
Optilab rEX User’s Guide (M1500 Rev. D)
6-5
Chapter 6: Off-Line Measurements
6-6
Optilab rEX User’s Guide (M1500 Rev. D)
7
In-Line HPLC Detection
This chapter provides details about preparing samples for optimal in-line
operation and measurement.
CONTENTS
PAGE
7.1 Conditions for In-Line Operation..................................................... 7-2
7.2 Sample Preparation........................................................................ 7-3
7.3 Measurement.................................................................................. 7-3
Optilab rEX User’s Guide (M1500 Rev. D)
7-1
Chapter 7: In-Line HPLC Detection
7.1 Conditions for In-Line Operation
In order to use the high sensitivity Optilab rEX successfully, the following
are recommended:
•
Solvents should be pre-mixed and stored in a covered reservoir. For
the lowest possible baseline noise, a stirrer should be used in the
solvent flask. The solvent should be degassed by vacuum, sonication,
or boiling, and blanketed with an inert gas—such as helium or argon—
that has a low solubility in the solvent. An in-line degasser may be
used effectively. The use of two or more pumps and a mixing chamber
is not recommended since even a one part per million deviation in the
mixed solvent ratio causes large deviations in the dRI signal, and
there are no known mixing techniques that are able to maintain a one
part per million level of stability.
•
Thermal control and/or insulation of the system components are
important in order to obtain good results, particularly in:
•
the column(s)
•
the eluent before the column(s)
•
the Optilab rEX itself
“Main Tab” on page 5-3 outlines how to control the Optilab rEX temperature. The Optilab rEX is extremely stable thermally, so unless
the ambient temperature fluctuates considerably, the Optilab rEX
should be able to achieve a stable temperature.
•
A pump with a constant flow rate is required, and regularly checking
the pressure is an important routine in HPLC. A slowly increasing or
unstable pressure is an indication that the chromatography conditions
are changing, most often due to:
•
blockage in the solvent reservoir filter
•
blockage in the in-line filter after the pump
•
blockage in the column
•
malfunctioning pump
•
air or gas in the system
These problems often create an unstable baseline due to an unstable
column environment. The instabilities result in fluctuating solution
density, hence a changing RI, which the Optilab rEX refractometer
measures faithfully! The result is a signal with oscillations, spikes, or
drift.
•
7-2
When changing solvents, special care should be taken to avoid leaving
residues of the old solvent in the chromatography system. It is best to
work with pre-conditioned columns and to change solvents with the
columns by-passed. The Optilab rEX may be used as a monitor during
Optilab rEX User’s Guide (M1500 Rev. D)
Sample Preparation
this process, to ensure that solvents are thoroughly flushed through
the detector. “Purging the Optilab rEX” on page 4-9 describes solvent
change procedures.
The pump pressure should be noted regularly, and the system should be
checked for any short-term variations in flow rate, eluent, or operating
temperature. If variations are discovered, appropriate action should be
taken as recommended in the user’s manual for the questionable
component.
For further information regarding injection procedures, pumps, thermostats, etc., refer to the various instruction manuals for these devices and to
the broad literature on HPLC.
7.2 Sample Preparation
To avoid contamination of the column and obtain the best possible separation, it is important to have a clean sample solution.
Additionally, the following guidelines may be helpful in sample
preparation:
•
Solvent used for sample preparation should have the same composition as the eluent solution. Only HPLC-grade solvents should be used.
•
Sample dissolution may be encouraged by shaking or swirling, homogenizing, or sonication. Care should be taken to avoid precipitation from
excessively high concentrations. Several hours of dissolving time may
be required for the sample to fully dissolve.
•
Particle removal by filtration (0.2–0.5 µm filter) and the use of a guard
column is highly recommended.
•
Degassing improves the quality of the solvent/sample analysis.
7.3 Measurement
1. Prior to injecting a sample, confirm that the baseline is stable.
2. Zero the instrument by navigating to the LCD display Main tab and
pressing ENTER on the Zero button.
Optilab rEX User’s Guide (M1500 Rev. D)
7-3
Chapter 7: In-Line HPLC Detection
7-4
Optilab rEX User’s Guide (M1500 Rev. D)
8
Service and Maintenance
This chapter provides detailed instructions on minor maintenance tasks
that can be performed by the user on the Optilab rEX.
CONTENTS
8.1
8.2
8.3
8.4
8.5
PAGE
Replacing the LED/Fiber Light Source ........................................... 8-2
Cleaning After a Fluid Leak ............................................................ 8-11
Cleaning the Air Intake Filter .......................................................... 8-12
Changing a Fuse ............................................................................ 8-12
Optilab rEX Firmware Upgrades..................................................... 8-13
Optilab rEX User’s Guide (M1500 Rev. D)
8-1
Chapter 8: Service and Maintenance
8.1 Replacing the LED/Fiber Light Source
The Optilab rEX contains a light source consisting of a Light Emitting
Diode (LED) coupled to an optical fiber. The wavelength of the light
emitted from the LED defines the measurement wavelength.
You can change the measurement wavelength of the Optilab rEX by
changing the LED/fiber light source. If the replacement LED/fiber light
source has a different wavelength than the current light source, you will
need to change the wavelength setting on the Optilab rEX front panel.
CAUTION: Light sources with different wavelengths have different power requirements. It is possible to destroy a light source if you do not carefully follow
the procedure in the sequence that follows.
It may also be advisable to change the LED/fiber light source if the optical
power output from the LED/fiber has significantly diminished and the
instrument performance is being compromised. Refer to Chapter 9, “Troubleshooting” to determine if the LED/fiber light source needs to be
replaced.
Use the steps in the subsections that follow to change the Optilab rEX
LED/fiber light source.
Items required:
•
•
•
•
1.5 mm hex driver (provided with the instrument)
2.0 mm hex driver (provided with the instrument)
2.5 mm hex driver (provided with the instrument)
Replacement LED/fiber light source
Setting the Percent Max Power to Zero
1. On the Optilab rEX front panel, go to the System tab. Press TAB to
move to the LED button and press ENTER.
8-2
Optilab rEX User’s Guide (M1500 Rev. D)
Replacing the LED/Fiber Light Source
2. In the LED Intensity dialog, tab to the Percent max power field, set
the value to “0”, and press ENTER. Close the LED Intensity dialog.
Note that the Optilab rEX Low Light Alarm is activated when you set
the LED percent max power to 0.
3. To ensure that the LED max power setting is saved at 0%, you must
restart the device by navigating to the Restart button in the System
tab and allowing the Optilab rEX to shutdown and restart.
4. After the instrument has fully restarted, power off the Optilab rEX
and disconnect the power cord from the instrument.
Optilab rEX User’s Guide (M1500 Rev. D)
8-3
Chapter 8: Service and Maintenance
Removing the Old LED/Fiber Light Source
CAUTION: It is strongly recommended that you wear an anti-static wristband
whenever you open the Optilab rEX to help prevent potential damage to
the instrumentation from electrostatic discharge.
WARNING: Be sure that the power cord is disconnected from the instrument before
removing the cover.
1. Using a 2 mm hex driver, remove the four screws securing the rEX
cover to the chassis. Then, remove the cover.
8-4
Optilab rEX User’s Guide (M1500 Rev. D)
Replacing the LED/Fiber Light Source
2. The optical fiber mount is located on the Optilab rEX electronics board
pictured below. Using a 1.5 mm hex driver, loosen both of the optical
fiber mount screws. Remove one screw entirely, but do not remove the
other screw. Remove the optical fiber from the mount.
Remove screw
Loosen screw;
do not remove
3. Gently disconnect the LED/fiber light source two-pin connector from
the utility board at the spot labeled P1.
Optilab rEX User’s Guide (M1500 Rev. D)
8-5
Chapter 8: Service and Maintenance
4. Using a 2.5 mm hex driver, unscrew all eleven screws on the thermal
housing top plate. Remove the top plate and set it aside.
5. Remove the topmost block of thermal foam. Next remove the two small
blocks of foam above the optical fiber within the thermal housing. This
exposes the optical fiber connection port. Set blocks aside for future
use.
Optical fiber
connection port
8-6
Optilab rEX User’s Guide (M1500 Rev. D)
Replacing the LED/Fiber Light Source
6. Gently unscrew the optical fiber at the optical fiber connection port by
hand. Once it is fully unscrewed, slide the optical fiber out of the thermal housing. You may now remove the LED/fiber light source from the
Optilab rEX.
Unscrew and slide
out of housing
CAUTION: Unless you are replacing a damaged LED/fiber light source, you should
store the removed fiber in a safe place. Take care to ensure that extra curvature is not introduced into the fiber during storage; this helps prolong
the LED/fiber light source lifetime.
Optilab rEX User’s Guide (M1500 Rev. D)
8-7
Chapter 8: Service and Maintenance
Installing the New LED/Fiber Light Source
1. Slide the new optical fiber connector into the housing; the
fiber should slide easily into
place. Gently screw the new
fiber into the connection port
(clockwise). Ensure a tight
connection by hand, but do not
over-tighten. The connector
threads should meet very little
resistance while being screwed
into the connection port. When
secured, no connection threading should be visible.
No threads visible
New LED/fiber
light source
2. Place the metal cylinder portion of the LED/fiber light
source in the optical fiber
mount. Secure the fiber in the
clamp by tightening the two
screws. (See [2] in the picture
that follows.)
3. Connect the two-pin LED/fiber light source connector to the circuit
board at the position marked P1. (See [3] in the picture that follows.)
4. Move the optical fiber off of the Optilab rEX power supply, and place
the optical fiber coil in the gap between the Optilab rEX thermal housing and the power supply. Be careful not to introduce much extra curvature into the optical fiber during this process. (For the proper coiling
position, see [4] in the picture that follows.)
[4]
[2]
[3]
8-8
Optilab rEX User’s Guide (M1500 Rev. D)
Replacing the LED/Fiber Light Source
5. Replace the two small blocks of thermal foam over the optical fiber,
being careful to align the slit in the small, cylindrical foam piece with
the optical fiber. Place the large block of thermal foam back on top of
the Optilab rEX optical bench, being careful to line up the holes in the
foam with the nitrogen purge port and thermostat protruding from the
top of the optical bench.
6. Align the tubing, cables, and ribbon cable with their respective slots in
the thermal housing. Place the thermal housing top plate on top of the
thermal housing. Using a 2.5 mm hex driver, secure all 11 screws into
the thermal housing. Be careful not to pinch any cables or tubing.
7. Replace the Optilab rEX cover and seal it with the four screws.
8. Connect the power cord, and switch the power on.
CAUTION: Do not adjust the LED percent max power before changing the wavelength
setting (if necessary) as described in the next subsection.
Changing the Wavelength Setting
If the new LED/fiber light source has a different wavelength than the
previous light source, you need to change the wavelength setting on the
Optilab rEX front panel. Different wavelength light sources have different
power requirements, and it is possible to destroy the LED/fiber light
source if care is not taken to set the wavelength correctly.
To change the front panel LED/fiber light source wavelength setting,
follow these steps:
1. Navigate to the System tab on the Optilab rEX front panel. Tab to the
Wavelength Change button and press ENTER.
2. In the Change Wavelength dialog, enter the new wavelength in nm,
and activate the OK button. The new wavelength will be shown in the
Wavelength field of the System tab.
3. Navigate to the Restart button in the System tab and allow the Optilab rEX to shutdown and restart.
Optilab rEX User’s Guide (M1500 Rev. D)
8-9
Chapter 8: Service and Maintenance
Optimizing the LED/Fiber Light Source
CAUTION: Be sure that the correct wavelength is set on the Optilab rEX front panel
as described in the previous section. It is possible to destroy the LED/fiber
light source if you adjust the light source Percent max power when using
the incorrect wavelength setting.
Note:
If the Optilab rEX was disconnected from flow during the replacement
procedure, flush the flow cell with your mobile phase before running the
optimization procedure. The LED Optimization procedure fails if there is a
bubble in the flow cell.
1. In System tab, press TAB to move to the LED button and press
ENTER.
2. In the LED Intensity dialog, tab to the Optimize button and press
ENTER.
The optimization process iteratively evaluates your system's optimum
LED settings. Once optimization is complete, you may close the LED
Intensity dialog.
Different LED wavelengths have different optimal and low light threshold
voltages. These values are adjusted automatically in the Optilab rEX
when you select a new LED/fiber light source wavelength.
8-10
Wavelength (λ) Range
(nm)
Optimal LED Intensity
(V)
LED Intensity Low Light
Threshold (V)
λ <= 568
6.2
4
568 <= λ< 725
7.8
5
725 <= λ
7.8
5
Optilab rEX User’s Guide (M1500 Rev. D)
Cleaning After a Fluid Leak
8.2 Cleaning After a Fluid Leak
Liquid from leaks of internal or external fittings is directed to a liquid leak
well inside the instrument. If a liquid leak occurs, an optical liquid sensor
in that well senses the presence of the liquid and activates an alarm that
may be seen on the LCD display (see “Alarms Tab” on page 5-5 for a
description of the Alarms tab), and activates an Alarm Out signal that
may be used to disable a pump.
The well in which the liquid collects has two chambers. The chamber
directly beneath the liquid leak detector, which is also the one that is more
difficult to access, is the chamber that needs to be emptied and cleaned
(see Figure 8-1).
Front Panel
Liquid Leak Detector
Liquid Leak Well
Figure 8-1: Liquid Leak Chamber
To clean a liquid leak, follow these steps:
1. Disable the pump or otherwise prevent additional liquid from being
sent into the Optilab rEX.
2. Disconnect the power cord from the instrument.
3. Using a 2mm ball driver, remove the four screws that secure the cover
to the instrument.
4. Lift the cover at the front and pull forward to remove.
CAUTION: Be sure to wear gloves and other protection appropriate for handling the
solvent that has leaked.
5. Using absorbent paper or cotton, soak up as much as possible from the
liquid leak well.
When the liquid leak well has been emptied, the liquid leak alarm
should turn off. A slight wetting of the well should not be sufficient to
set off the liquid leak alarm.
Optilab rEX User’s Guide (M1500 Rev. D)
8-11
Chapter 8: Service and Maintenance
6. If the liquid leak well contains residue from the leak, use a syringe to
flush the liquid leak well with a pure solvent that is co-miscible with
the solvent that has leaked (see “Purging the Optilab rEX” on page 4-9
for a list of solvent miscibilities).
7. Repeat step 5 to remove any pure solvent you used to clean the liquid
leak well.
8. Install the cover and secure it with the four screws you removed in
step 3.
8.3 Cleaning the Air Intake Filter
Periodically remove and clean the foam filter for the instrument’s air
intake fan. The air intake fan is located on the rear panel of the instrument next to the power connector on the left (see Figure 2-2).
1. Lift the filter bracket off of the rear panel of the instrument and
remove the air filter from the filter bracket.
2. Wash the air filter with mild soap and water.
3. When dry, place the air filter back into the filter bracket.
4. Attach the filter bracket with filter back onto the rear panel of the
instrument.
8.4 Changing a Fuse
The fuses are located in the power connection socket (see Figure 2-2).
In order to change a fuse, you need the following items:
•
Tool for prying the AC Power module cover off, such as a small-bladed
screwdriver.
•
Fuses from the spares supplied in the accessory kit.
To replace a fuse, follow these steps:
1. Disconnect the power cord from the instrument.
2. Open the cover of the AC Power module using a small blade screwdriver or similar tool.
3. Replace the old fuses with new ones. Use only 2 Amp, 240 V fuses.
Note:
Be sure to use the correct fuse for the voltage.
4. Replace the cover of the AC Power module.
5. Reconnect the power cord.
8-12
Optilab rEX User’s Guide (M1500 Rev. D)
Optilab rEX Firmware Upgrades
8.5 Optilab rEX Firmware Upgrades
For peak performance and stability of your Optilab REX, check regularly
for the most recent firmware. The rEX firmware upgrades are available at
the wyatt.com support center. You will be required to log in. For help
logging in, visit the www.wyatt.com support center signup page or send
email to [email protected].
Optilab rEX User’s Guide (M1500 Rev. D)
8-13
Chapter 8: Service and Maintenance
8-14
Optilab rEX User’s Guide (M1500 Rev. D)
9
Troubleshooting
This chapter provides details about troubleshooting procedures for the
Optilab rEX.
CONTENTS
9.1
9.2
9.3
9.4
PAGE
Low Light Alarm.............................................................................. 9-2
Temperature Will Not Set Below 20 C ............................................ 9-3
Noisy Baseline................................................................................ 9-4
Microsoft Windows Encounters Problems ...................................... 9-4
Optilab rEX User’s Guide (M1500 Rev. D)
9-1
Chapter 9: Troubleshooting
9.1 Low Light Alarm
A low light alarm occurs if the light intensity on the photodiode array
drops too low. Such a situation occurs any time the refractive index difference between the sample and reference fluids is large enough to cause the
light beam to move off the end of the photodiode array.
This happens in the following situations:
•
•
You are changing solvents.
•
The sample refractive index is changing dramatically, such as when a
very concentrated solution is injected directly into the Optilab rEX.
When injecting a very concentrated solution directly into the Optilab
rEX, the low light alarm may sometimes be observed at the leading
and trailing edge of the injection. A low light condition during the
leading and trailing edge of an injection does not observably effect the
accuracy of the measurement.
The sample fluid refractive index is very different from the reference
fluid refractive index.
The low light alarm activates if the voltage measured from the photodiode
array, which is proportional to the light intensity on the photodiode array,
drops below a threshold value of 5 V for 660 or 690 nm light sources. See
“LED Intensity Dialog” on page 5-11 for low light voltage thresholds for
LED/fiber light sources with other wavelengths.
With the light source off, the voltage measured from the photodiode array
is about 2 V. The maximum (saturation) voltage from the photodiode array
is about 8 V, regardless of the intensity of the light on the array.
The voltage measured from the photodiode array may be seen by navigating to System>LED, and observing the value in the Light Intensity dialog.
The value of the voltage in this dialog can give an indication of the
problem causing a low light alarm.
In addition to the expected low light condition that arises when changing
solvents or injecting a concentration that is beyond the capabilities of the
Optilab rEX, other reasons the light intensity on the photodiode array
may be too low are as follows:
9-2
•
LED Off: On the System tab, the LED dialog allows you to turn the
LED/fiber light source On and Off. Check that the LED/fiber light
source is On.
•
Bubble in the Flow Cell: If the LED light source is on, but the
voltage read from the photodiode array is low, there may be a bubble
in the flow cell. Typically, a bubble in the flow cell causes intermittent
episodes of low light and large noise. To prevent air bubbles from
forming in the flow cell, be sure to always use degassed solvents.
Optilab rEX User’s Guide (M1500 Rev. D)
Temperature Will Not Set Below 20 C
To dissolve air bubbles present in the flow cell, flow degassed solvent
through the Optilab rEX in purge mode. Reduce the system temperature as low as is practicable (20 °C without dry gas input, 4 °C with
dry gas input), and place a restriction capillary on the OUT port from
the Optilab rEX to increase the pressure in the flow cell by 10-15 psi.
The lower temperature and higher pressure increase the rate at which
the bubble is dissolved. With water as the solvent and a flow rate of 1
mL/minute, a 60 cm run of 0.010" ID tubing or a 4 cm run of 0.005" ID
tubing produces about 15 psi back pressure. Purge in this state for several hours to be sure that the bubble is 100% dissolved.
•
Light source dimmed with time: If the LED light source is on, and
the voltage read from the photodiode array is stable but slightly below
a threshold value, the light source may simply have dimmed
somewhat with time. See Table 5-2 for a table of low light voltage
thresholds for LED/fiber light sources with other wavelengths.
Increasing the power to the light source increases the intensity of light
on the photodiode array. When the voltage read from the photodiode
array rises above the threshold value, the Low Light alarm deactivates. Press the Optimize button to have the instrument automatically
set the optimal power to the LED/fiber light source. Changing the
power to the light source does not effect the instrument calibration
constant.
•
Light source burned out: If the LED light source is On and the
system has been carefully purged with degassed solvent, but the
voltage read from the photodiode array is still near 2 V, then the light
source may be burned out. The light source is easily replaceable,
taking about 15 minutes from start to finish. Contact Wyatt Technology Corporation for a replacement LED/fiber light source.
9.2 Temperature Will Not Set Below 20 C
For sub-ambient operation, dry gas must be slowly flowed into the cool
thermal environment to prevent water vapor from condensing on the electronics or optics.
The Optilab rEX contains a gas pressure sensor to measure the pressure
of the dry gas supplied to it. It will not set the temperature set point below
20 °C unless at least 20 psi of pressure is sensed. If dry gas of sufficient
pressure is supplied to the Optilab rEX and the temperature is set below
20 °C, but the gas pressure subsequently drops below 20 psi, then the temperature set point is automatically set to 20.5 °C.
Optilab rEX User’s Guide (M1500 Rev. D)
9-3
Chapter 9: Troubleshooting
9.3 Noisy Baseline
If the baseline noise of the instrument seems excessive, try the following:
1. Check that the LED light source is On, and that no Low Light Alarm
exists as described in “Low Light Alarm” on page 9-2.
2. Un-plumb the Optilab rEX from any flow system. Place a plug in the
OUT port, and leave the IN port open to the atmosphere. See if the
noise still exists.
If the noise no longer is present, then the noise could have its origin in the
chromatographic system, or could be due to a small bubble in the flow cell
that is forced into the measurement region only under flow conditions. Use
a syringe to inject solvent by hand into the Optilab rEX. If the noise is still
not present, then the noise probably has its origins in the chromatographic
system. Refer to “Conditions for In-Line Operation” on page 7-2 for ways
to reduce noise in chromatographic systems.
If the noise is intermittent during flow conditions, or remains in the
absence of flow, the noise may be due to a bubble in the flow system that is
small enough to not block light through the system, but large enough to
significantly effect the measurement. Follow the procedure for eliminating
bubbles outline in “Low Light Alarm” on page 9-2.
If the baseline noise persists, contact Wyatt Technology Corporation.
9.4 Microsoft Windows Encounters Problems
If the Microsoft Windows operating system on the LCD display encounters
a problem that causes it to freeze or crash, the Optilab rEX reboots the
operating system within one minute. You can use the power switch on the
front panel to turn the Optilab rEX off and on if you want to reboot the
machine yourself.
Experiments in progress when the operating system crashes must be
restarted.
9-4
Optilab rEX User’s Guide (M1500 Rev. D)
A
Acronyms and Abbreviations List
This appendix contains a list of acronyms and abbreviations used in this
manual.
CONTENTS
PAGE
A.1 Acronyms and Abbreviations.......................................................... A-2
Optilab rEX User’s Guide (M1500 Rev. D)
A-1
Appendix A: Acronyms and Abbreviations List
A.1 Acronyms and Abbreviations
The following acronyms and abbreviations are used in this manual:
Item
Meaning
AC
alternating current
Amp
Ampere
aRI
absolute refractive index
°C
Centigrade
cm
centimeters
DC
direct current
DHCP
Dynamic Host Configuration Protocol
dRI
differential refractive index
g
gram
GPa
Gigapascal
HPLC
high pressure liquid chromotography
Hz
Hertz
ID
inside diameter
in.
inch
IP
Internet Protocol
LAN
local area network
LED
light emitting diode
mg
milligram
MHz
Megahertz
MPa
Megapascal
µL
µm
microliter
micrometer
mL
milliliter
mm
millimeter
mV
millivolt
nm
nanometer
NMOS
n-doped metal/oxide semiconductor
OD
outside diameter
ppm
parts per million
psi
pounds per square inch
RI
refractive index
RIU
refractive index unit
STP
standard temperature and pressure = 0 °C and 1 atmosphere of pressure
TTL
transistor-transistor logic
V
Volt
VAC
Volts alternating current
VDC
Volts direct current
A-2
Optilab rEX User’s Guide (M1500 Rev. D)
B
Operating Principles and Theory
This appendix provides a basic overview of the theory and operation of the
Optilab rEX.
CONTENTS
PAGE
B.1 Basic Principles .............................................................................. B-2
B.1.1 Conventional Flow Cell ............................................................. B-2
B.1.2 Optilab rEX Flow Cell ................................................................ B-3
B.2 Measurement of the Beam Deflection Angle .................................. B-4
B.2.1 Conventional Split Photodiode Based Instrument .................... B-4
B.2.2 Wyatt Technology Corporation Beam Positioning Technology .. B-4
Optilab rEX User’s Guide (M1500 Rev. D)
B-1
Appendix B: Operating Principles and Theory
B.1 Basic Principles
B.1.1 Conventional Flow Cell
The Optilab rEX is a special variation of the deflection-type differential
refractometer. For this type of differential refractometer, a light beam
passes through a flow cell containing reference and sample fluids, and
undergoes an angular deflection based upon the refractive index difference
between the two fluids. A conventional deflection type differential refractometer flow cell is shown in Figure B-1.
Figure B-1: Conventional deflection type flow cell
For this conventional flow cell, if the sample refractive index ns and reference fluid refractive index nr are identical, then the light beam exits the
cell in a direction parallel to the incoming beam. If ns is not equal to nr,
then the light beam exits the cell at some angle θ to the incoming beam. To
the first order, this angle is proportional to the refractive index difference
between ns and nr. In addition to any angular deflection, the light beam
undergoes a slight translation due to passage through the material comprising the body of the flow cell (i.e., the window between the sample and
reference fluid chambers). The optical system inside the differential
refractometer must separate angular deflections from translation of the
light beam.
To measure the refractive index difference between two fluids, both
sample and reference chambers are filled with the reference fluid, and the
starting position of the light beam is noted. This is considered the “zero”
position. The reference chamber is then capped, trapping the reference
fluid inside. Fluid is then directed through the sample chamber, and
changes in the refractive index of that fluid cause an angular deflection of
the light beam. Measurement of the light beam angular deflection yields
the refractive index difference between the sample fluid and the reference
fluid.
B-2
Optilab rEX User’s Guide (M1500 Rev. D)
Basic Principles
B.1.2 Optilab rEX Flow Cell
The Optilab rEX differs from the conventional design because its flow cell
contains a novel feature to allow, under certain conditions, the measurement of the absolute refractive index (aRI) of a fluid, as well as the
differential refractive index (dRI) between two fluids. The flow cell in the
Optilab rEX is shown in Figure B-2. The reference chamber has a non-90
angle on its exit face.
Figure B-2: Optilab rEX differential and absolute refractive index flow cell
This unique flow cell has an extra internal wedge in its reference chamber.
The extra wedge lends an additional angular deflection φ to the light
beam. The value of the angle φ depends upon the wedge angle and the
refractive index difference between the reference fluid and the quartz body
of the Optilab rEX flow cell. Knowing the wedge angle and the refractive
index of the quartz, a measurement of φ yields the refractive index nr of
the reference fluid. In practice, the wedge angle is determined by measuring the angular deflection φ for a few fluids of known refractive index.
The total angular deflection of the light beam depends upon both the
refractive index difference between the sample and reference fluids and
the aRI of the reference fluid. To determine the aRI of a fluid, it is required
that the same fluid be present in both the sample and reference chambers.
With the same fluid in the sample and reference chambers, the refractive
index difference is zero, and any angular deflection of the light beam is
due solely to the aRI of the reference fluid.
Measurement of the refractive index difference between two fluids is
accomplished by noting the angular deflection φ of the light beam at the
beginning of a data run, and considering this the “zero” position of the
light beam.
Optilab rEX User’s Guide (M1500 Rev. D)
B-3
Appendix B: Operating Principles and Theory
B.2 Measurement of the Beam Deflection Angle
B.2.1 Conventional Split Photodiode Based Instrument
Measurement of the deflection of the beam of light after it has passed
through the flow cell is the basic measurement made in a deflection type
refractometer. This deflection is proportional to the dRI of the two fluids
being measured. Conventionally, a split photodiode is used to measure the
light beam angular deflection, as pictured in the illustration below.
The split photodiode contains two photodiode light detectors placed side to
side. As the light beam changes angle, the beam moves away from one
photodetector and onto the other. The voltage difference between the two
detectors gives a measure of the light beam position, which is proportional
to the light beam angular deflection, which is in turn proportional to the
differential refractive index.
The precision of a split photodiode detector based instrument is limited by
the precision with which the voltages may be read from the two photodetectors and the intensity stability of the light source. The maximum signal
a split photodiode detector may observe depends upon the width of the
light beam and the width of the photodetectors. Once the light beam has
walked entirely off of one photodetector and onto the other, there is no way
to determine the beam position.
B.2.2 Wyatt Technology Corporation Beam Positioning Technology
Rather than using two photodetectors, the Optilab rEX contains 512 light
measuring elements in one photodiode array. Each element of the photodiode array, called a pixel, precisely measures the intensity of light
impacting upon it.
The Optilab rEX records voltages from each of the 512 elements of the
photodiode array 10–20 times per second. To obtain the most precise
possible measurement, the signal from each element is measured many
times and the results averaged together. Hundreds of thousands of voltage
measurements per second are required. The data from the 512 pixels are
analyzed using mathematical algorithms to determine the position of the
light beam on the array.
B-4
Optilab rEX User’s Guide (M1500 Rev. D)
Measurement of the Beam Deflection Angle
The computational power to perform these mathematically intensive operations at such rates was unavailable 15 years ago, but now fits into the
small Pentium-class processor inside your Optilab rEX. Using a photodiode array and advanced mathematical analysis techniques, the light
beam position may be measured to within about 25 Angstroms. The photodiode array is 1.3 cm long, and so the beam may move more than a
centimeter before it slides off the end of the photodiode array.
Optilab rEX User’s Guide (M1500 Rev. D)
B-5
Appendix B: Operating Principles and Theory
B-6
Optilab rEX User’s Guide (M1500 Rev. D)
C
Optilab rEX Specifications
This appendix provides specification details for the Optilab rEX
instrument.
CONTENTS
PAGE
C.1 Specifications ................................................................................. C-2
Optilab rEX User’s Guide (M1500 Rev. D)
C-1
Appendix C: Optilab rEX Specifications
C.1 Specifications
Differential Refractive Index (dRI)
Range and Sensitivity:
Range (RIU)
– 0.0047 to + 0.0047
Peak-to-Peak Noise (RIU)
±2 x 10–9 (see note)
Absolute Refractive Index (aRI)
Range and Sensitivity:
Range (RIU)
1.2 to 1.8 RIU
Sensitivity (RIU)
± 0.002 RIU
Fluid Volumes
Flow Cell:
7.4 µL
Inlet tubing (0.010” ID):
44 µL
Outlet tubing (0.030” ID):
370 µL
Power Requirements:
AC 100/115/220/240 V, 50/60 Hz
Dynamic Range:
21+ bits only via digital communication
Response Time:
0.1 to 5.0 seconds, user selectable
Light Source:
690 nm or 660 nm (± 10 nm) LED light source,
standard
Sample Temperature Control
Range:
4°C to 50 °C, temperature regulated
Temperature Regulation:
± 0.005 °C
Maximum System Pressure:
30 psi (2 bar)
Maximum Cell Pressure:
100 psi (7 bar)
Safety Sensors:
Vapor and liquid (leak)
CPU:
300 MHz National Geode Processor
Display / User Interface:
6.4” 16-bit color high resolution LCD display
Inputs and Outputs:
Analog In:
16 bit ±10 V Analog/Digital for auxiliary user
data
Analog Out:
16 bit Digital/Analog for dRI data
Inputs:
Zero, Purge, Recycle, Auto Inject, Alarm In
Output:
Auto Inject Retransmit, Alarm Out External,
Solenoid Recycle Valve. 12 VDC solenoid valve
(sold separately or user supplied) to switch
automatically between waste and recycle
Digital Communication:
Ethernet
Dimensions:
168 mm x 357 mm x 595 mm (H x W x D)
Weight:
11.5 kg
Note: Short term peak-to-peak noise is measured as per ASTM-E1303-95(2000) using a
4-second time constant and temperature controlling at 25 °C.
C-2
Optilab rEX User’s Guide (M1500 Rev. D)
D
Wire Colors
This appendix provides details about earlier revisions of the generalpurpose cable supplied by Wyatt Technology Corporation.
CONTENTS
PAGE
D.1 Earlier Cable Revisions .................................................................. D-2
Optilab rEX User’s Guide (M1500 Rev. D)
D-1
Appendix D: Wire Colors
D.1 Earlier Cable Revisions
Wire colors and associated signal connections for the most recent revision
of the Wyatt general-purpose cable are listed in Section 4.1.2, “Signal Connectors” on page 4-2. Earlier revisions of the general-purpose cable have
the wire colors and associated signal connectors shown in Figure D-1 and
Table D-1.
Pin
Wire Color
1
Orange
2
White/Orange
3
Blue
4
White/Blue
5
Green
6
White/Green
Figure D-1: RJ-12 Connector and Pinouts
Table D-1: RJ-12 Signal Function
Optilab rEX
Connector
RJ-12 Connector Wire Signal
Orange
D-2
White/
Orange
Blue
White/
Blue
Zero In
Signal
Signal
Ground
Purge In
Signal
Signal
Ground
Recycle In
Signal
Signal
Ground
Alarm In
Signal
Signal
Ground
Auto Inject In
Signal
Signal
Ground
Analog In
Positive
Negative
Analog Out
Positive
Negative
Recycle Out
Signal
Signal
Ground
Alarm Out
Signal
Signal
Ground
Auto Inject Out
Contact
Contact
Green
White/
Green
Ground
Ground
Optilab rEX User’s Guide (M1500 Rev. D)
E
Instrument Connectivity
This appendix provides instrument connectivity instructions are current
as of January, 2005. Please visit the www.wyatt.com support center for
current information. Login access is required. For login help, visit the
www.wyatt.com support center signup page or send email to
[email protected].
CONTENTS
E.1
E.2
E.3
E.4
E.5
E.6
E.7
E.8
PAGE
Introduction..................................................................................... E-2
Components Used.......................................................................... E-3
Connecting to a LAN ...................................................................... E-8
Connecting via USB ....................................................................... E-12
Connecting via Ethernet When Not on a LAN ................................ E-15
Instrument Network Settings .......................................................... E-17
Accessing Instruments with ASTRA V............................................ E-18
Troubleshooting and Diagnostics ................................................... E-19
Optilab rEX User’s Guide (M1500 Rev. D)
E-1
Appendix E: Instrument Connectivity
E.1 Introduction
These instructions contain a pictorial overview for connecting your
Optilab rEX to a computer for data collection. The instructions are divided
into the following topics:
•
Components to be used for instrument connectivity (page E-3). All
users should read this section.
•
Instructions for connecting instruments to a computer via a Local Area
Network (LAN) (page E-8). Read this section or the next section
depending on your configuration.
•
Instructions for connecting instruments to a computer via USB
(page E-12).
•
Instructions for connecting instruments to a computer that is not on
the LAN (page E-15).
•
Instrument front panel network settings (page E-17). All users should
read this section.
•
Accessing instruments via ASTRA V (page E-18). Read this section if
you use ASTRA V.
•
Trouble shooting and diagnostics (page E-19). Read this section if you
experience problems connecting to your instrument.
This appendix provides instrument connectivity instructions are current
as of January, 2005. Please visit the www.wyatt.com support center for
current information. Login access is required. For login help, visit the
www.wyatt.com support center signup page or send email to
[email protected].
E-2
Optilab rEX User’s Guide (M1500 Rev. D)
Components Used
E.2 Components Used
E.2.1 Instrument Connections
Figure E-1 shows a detail of the instrument back panel. The yellow arrow
points to the Ethernet port, which is to be used for all connections in these
instructions.
The built-in USB port exhibits technical problems on some computers, and
Wyatt Technology recommends using the Ethernet port instead. Please
see “Connecting via USB” on page E-12 for instructions on establishing a
USB connection.
Figure E-1: Detail of the instrument back panel
Optilab rEX User’s Guide (M1500 Rev. D)
E-3
Appendix E: Instrument Connectivity
E.2.2 LAN Connection
Figure E-2 shows a typical wall socket connection to a Local Area Network
(LAN). If you are going to connect the instrument to a LAN, you will need
access to this type of socket.
Figure E-2: Wall socket LAN connection
E.2.3 Computer Connections
Computer connections can be made via either an Ethernet or USB port on
the computer. “Connecting to a LAN” on page E-8 and “Connecting via
Ethernet When Not on a LAN” on page E-15 describe instrument connections made via the Ethernet port. “Connecting via USB” on page E-12
describes connections made via the USB port.
Figure E-3 shows the Ethernet (yellow arrow) and USB (green arrow)
ports on a standard laptop computer.
USB port
Ethernet port
Figure E-3: Ethernet and USB ports on the computer
E-4
Optilab rEX User’s Guide (M1500 Rev. D)
Components Used
E.2.4 Crossover Cable
A crossover cable can be used to make a direct connection from the instrument to an Ethernet port on a computer or to an Ethernet to USB adapter.
Note that the crossover cable shipped with Wyatt Technology instruments
is yellow to distinguish it from a standard Ethernet cable. Be careful to
only use the yellow crossover cable where indicated.
Figure E-4: Ethernet crossover cable shipped by Wyatt Technology
E.2.5 Ethernet Cable
A standard Ethernet cable is sometimes referred to as a patch cable, or a
straight-through cable to distinguish it from the crossover cable in Figure
E-4. Standard Ethernet cables provided by Wyatt Technology are black,
blue, white, or gray, but never yellow. (Yellow is reserved for the crossover
cable.) For these instructions, the Ethernet cable will always be black.
Figure E-5: Standard Ethernet cable
Optilab rEX User’s Guide (M1500 Rev. D)
E-5
Appendix E: Instrument Connectivity
E.2.6 Ethernet to USB Adapter
This device can be used to connect an Ethernet cable to a USB port on the
computer. Using this adapter, it is possible to have the computer connected to a LAN via the computer's Ethernet port, and the instruments
connected to the computer via USB. The Ethernet to USB adapter
supplied by Wyatt Technology will look similar to the one in Figure E-6.
Figure E-6: Standard Ethernet to USB adapter
The Ethernet cable is plugged into the port with the yellow arrow, and the
USB plug (green arrow) is plugged into a USB port on the computer.
The first time you connect an Ethernet to USB adapter to your computer,
you may be prompted to install USB drivers for the device. To do so, use
the CD supplied with the Ethernet to USB adapter, and follow the
Microsoft Windows instructions.
E-6
Optilab rEX User’s Guide (M1500 Rev. D)
Components Used
E.2.7 Ethernet Switch
Ethernet switches are used to connect several Ethernet cables to one
resource, such as the LAN socket in Figure E-2.
The Ethernet switch supplied by Wyatt Technology will look similar to the
five port switch shown below. Note that Ethernet cables can be connected
to the switch in any order or position. Also, the switch has an external AC
adapter (not shown) to provide power to the switch.
Figure E-7: Five-port Ethernet switch
Optilab rEX User’s Guide (M1500 Rev. D)
E-7
Appendix E: Instrument Connectivity
E.3 Connecting to a LAN
If an instrument is connected to a LAN, it can be accessed by any
computer plugged into the same LAN.
The following sections describe various configurations for connecting one
or more instruments to a LAN and possibly to a computer also. (For
example, to a computer running ASTRA V.)
These sections use a LAN wall socket like the one in Figure E-2.
E.3.1 One Instrument to LAN
Plug the instrument into a LAN wall socket using a standard Ethernet
cable (Figure E-5). The computer that is to communicate with the instrument must be on the same LAN.
Figure E-8: Connection for one instrument to LAN
E-8
Optilab rEX User’s Guide (M1500 Rev. D)
Connecting to a LAN
E.3.2 One Instrument and Computer to LAN
If there is only one LAN wall socket available for both the instrument and
computer, it is necessary to use an Ethernet switch (Figure E-7) to connect
both the computer and instrument to the LAN. In this configuration, the
computer can access the LAN and the instrument, and the instrument can
be accessed from any other computer on the LAN.
Figure E-9: Instrument and computer connected to LAN via Ethernet switch
Optilab rEX User’s Guide (M1500 Rev. D)
E-9
Appendix E: Instrument Connectivity
E.3.3 Multiple Instruments to LAN
If there is only one LAN wall socket available, two or more instruments
can be connected to the LAN via an Ethernet switch (Figure E-7). The
instruments can be accessed via any computer on the LAN.
Figure E-10: Two instruments connected to LAN via an Ethernet switch
E-10
Optilab rEX User’s Guide (M1500 Rev. D)
Connecting to a LAN
E.3.4 Multiple Instruments and Computer to LAN
If there is only one LAN wall socket available for multiple instruments
and a computer, it is necessary to use an Ethernet switch to connect both
the computer and instruments to the LAN. In this configuration, the
computer can access the LAN and the instruments, and the instruments
can be accessed from any other computer on the LAN.
Figure E-11: Two instruments and computer to LAN via an Ethernet switch
Optilab rEX User’s Guide (M1500 Rev. D)
E-11
Appendix E: Instrument Connectivity
E.4 Connecting via USB
If it is not possible or desired to have the instruments connected to a LAN,
you can connect to the instruments via USB. In this way, the instruments
can be isolated from the LAN, even while the computer maintains its own
Ethernet connection with the LAN.
E.4.1 One Instrument to USB via a Crossover Cable
Connect the yellow crossover cable (Figure E-4) from the instrument to the
Ethernet to USB adapter (Figure E-6). Plug the Ethernet to USB adapter
into an available USB port on the computer.
Figure E-12: One instrument to USB via yellow crossover cable
You may be prompted to install drivers for the Ethernet to USB adapter
the first time it is plugged into the computer. To install the drivers, insert
the CD that came with the adapter and follow the Windows instructions.
E-12
Optilab rEX User’s Guide (M1500 Rev. D)
Connecting via USB
E.4.2 One Instrument to USB Using an Ethernet Switch
Connect the instrument to the Ethernet switch using a standard Ethernet
cable (Figure E-5). Then connect the Ethernet switch to the Ethernet to
USB adapter using a standard Ethernet cable. Plug the Ethernet to USB
adapter into an available USB port on the computer.
Figure E-13: Connecting one instrument to USB using an Ethernet switch
You may be prompted to install drivers for the Ethernet to USB adapter
the first time it is plugged into the computer. To install the drivers, insert
the CD that came with the adapter and follow the Windows instructions.
Optilab rEX User’s Guide (M1500 Rev. D)
E-13
Appendix E: Instrument Connectivity
E.4.3 Multiple Instruments to USB
Two or more instruments can be connected to USB using an Ethernet
switch. Use a standard Ethernet cable to plug each instrument into the
Ethernet switch. Then connect the Ethernet switch to the Ethernet to
USB adapter using a standard Ethernet cable. Plug the Ethernet to USB
adapter into an available USB port on the computer.
Figure E-14: Connecting two instruments to USB via Ethernet switch and adapter
You may be prompted to install drivers for the Ethernet to USB adapter
the first time it is plugged into the computer. To install the drivers, insert
the CD that came with the adapter and follow the Windows instructions.
E-14
Optilab rEX User’s Guide (M1500 Rev. D)
Connecting via Ethernet When Not on a LAN
E.5 Connecting via Ethernet When Not on a LAN
If the computer is not on the LAN, it is possible to use the Ethernet port
directly to connect to the instruments.
E.5.1 One Instrument to Computer Using Crossover Cable
Connect the yellow crossover cable from the instrument directly to the
Ethernet port on the computer.
Figure E-15: Connecting one instrument to computer via yellow crossover cable
Optilab rEX User’s Guide (M1500 Rev. D)
E-15
Appendix E: Instrument Connectivity
E.5.2 One Instrument to Computer Using an Ethernet Switch
Connect the instrument to the Ethernet switch using a standard Ethernet
cable. Then connect the switch to the computer Ethernet port using a
standard Ethernet cable.
Figure E-16: Connecting instrument to computer via an Ethernet switch
E.5.3 Multiple Instruments to Computer Using an Ethernet Switch
Connect each instrument to the Ethernet switch using a standard
Ethernet cable. Then connect the switch to the computer Ethernet port
using a standard Ethernet cable.
Figure E-17: Connecting multiple instruments to computer via Ethernet switch
E-16
Optilab rEX User’s Guide (M1500 Rev. D)
Instrument Network Settings
E.6 Instrument Network Settings
Figure E-18 shows the standard settings on the Communications tab of
the instrument front panel that will work with all of the above connection
schemes.
Figure E-18: Standard instrument connectivity settings on front panel
On this tab, there is a choice for DHCP or Static IP. In general, this
setting can be left set to DHCP.
With DHCP, once the instrument is connected to a computer or LAN, the
IP address and subnet mask will be assigned automatically. This will
work even with the USB connections described in “Connecting via USB”
on page E-12.
When using DHCP, it might take several minutes for the IP address to be
assigned. During this time, the IP address and subnet mask on the front
panel will read 0.0.0.0. Once the IP address and subnet mask have been
assigned, both will be automatically updated on the front panel, and
should no longer read 0.0.0.0. At this point, it should be possible to connect
to the instrument from the computer.
If you want to use a static IP address and subnet mask, please contact
your IT department to obtain a valid address and mask.
Optilab rEX User’s Guide (M1500 Rev. D)
E-17
Appendix E: Instrument Connectivity
E.7 Accessing Instruments with ASTRA V
To access an instrument with ASTRA V after you have connected it as
described in this chapter, follow these steps:
1. From the main menu of ASTRA V, select System→ISI.
2. In the ISI dialog, click Add. You will see the Add ISI dialog:
3. Do one of the following depending on how your instrument is connected and whether you are using a static IP address:
•
If the instrument is connected to a LAN and you are not using a
static IP address: Click the Browse button in the Add ISI dialog,
and then navigate to the instrument on the network. The instrument will be located under Network Neighborhood→Entire
Network→Microsoft Windows Network→WORKGROUP.
The instrument name will match the name on the System tab of
the instrument front panel. It may take several minutes for the
instrument name to appear after it has first been plugged into the
LAN. Select the instrument and then click OK.
•
If the instrument is not connected to the LAN or you are using a
static IP address: Type the IP address from the instrument front
panel directly into the IP Address field in the Add ISI dialog. For
Domain, select WORKGROUP.
4. Click OK to close the Add ISI dialog, then close the ISI dialog.
5. From the main menu, select System→Instruments. The instrument
you selected should be shown in the Instruments dialog.
6. Select the instrument by clicking its icon, then click the View button.
The Diagnostic Manager application should launch, which can be used
to verify the instrument connection.
If it is not possible to connect to an instrument after following these
instructions, read “Troubleshooting and Diagnostics” on page E-19.
E-18
Optilab rEX User’s Guide (M1500 Rev. D)
Troubleshooting and Diagnostics
E.8 Troubleshooting and Diagnostics
If you are experiencing instrument connectivity problems, please read and
follow these steps. If you still cannot connect to your instrument after
using this section, please contact Wyatt Technology for assistance.
E.8.1 Windows XP Professional Service Pack 2
If your computer has Windows XP Professional Service Pack 2 installed,
you need to change some default configuration settings on your computer
before you can connect to an instrument. Please log in to the Support
Center on the Wyatt Technology web site (www.wyatt.com ) and download
the configuration instructions under Software→Computer Info, or
contact customer service at Wyatt Technology to obtain the instructions.
E.8.2 ASTRA V Settings
If the instrument is not connected to the LAN or you are using a static IP
address, it is critical that you type in the correct IP address and select
“WORKGROUP” for the domain as described in “Accessing Instruments
with ASTRA V” on page E-18.
If either of these is not correct, from the main menu of ASTRA V select
System→ISI, then first delete the incorrect ISI entry. Then click Add
and repeat the steps, verifying that you have typed in the correct IP
address and selected “WORKGROUP” as the domain.
E.8.3 Verifying Instrument Connections
If the above suggestions fail, please verify that the instrument is communicating with the computer.
Open a Windows Command Prompt window on the computer. On the
command line, type “ping” plus the IP address of the instrument as shown
on the instrument front panel (see Figure E-18). If the instrument is connected properly, the result should be similar to that shown in Figure E-19.
Figure E-19: Using ping to verify the instrument connection
Optilab rEX User’s Guide (M1500 Rev. D)
E-19
Appendix E: Instrument Connectivity
If the instrument is not connected properly, the result will be similar to
that shown in Figure E-20.
Figure E-20: Failure to connect to instrument using ping
E-20
Optilab rEX User’s Guide (M1500 Rev. D)
F
Warnings
This appendix provides a list of warnings that should be read and understood when using the Optilab rEX.
CONTENTS
F.1
PAGE
List of Warnings .............................................................................. F-2
Optilab rEX User’s Guide (M1500 Rev. D)
F-1
Appendix F: Warnings
F.1 List of Warnings
WARNING
If the power cord is connected, line voltages of 120-240 VAC, 50-60 Hz are
present within the system even when the power switch is off. Always disconnect the power cord before opening the instrument cover.
WARNING
High voltage is stored in the instrument power supplies for some time
(hours) after the instrument is switched off and the power cord is disconnected. Under no circumstances should the power supplies be accessed by
unqualified personnel.
WARNING
The Optilab rEX contains a “Class 1 LED Product per IEC 60825-1”,
which is a non-lasing LED coupled to an optical fiber. The LED in this
LED/fiber unit is mounted to the top electronics board in the Optilab rEX
near connector P3. The fiber brings the light from the LED into the optical
system. With the instrument off and the power cable disconnected, it is
safe to replace the LED/fiber unit. The LED/fiber unit should not be
altered or modified in any way.
WARNING
The instrument contains fluid. Under normal operating conditions, the
system may contain up to 0.5 mL of fluid introduced into the system by the
user. If a leak develops internal to the instrument, additional fluid may be
present in the system. The system has been designed to bring fluid leaks
to standard locations within the instrument, but there always exists the
possibility of fluid present in non-standard locations. Fluid introduced into
the instrument by the user or its vapors may be hazardous. Safety precautions appropriate to the fluid within the system should be taken under the
assumptions that the fluid may not reside in standard locations within the
instrument, and may not be contained by the instrument.
F-2
Optilab rEX User’s Guide (M1500 Rev. D)
Index
A
C
abbreviations, list of A-2
absolute RI (aRI) 1-2
calibration constant 5-9
measuring 6-5
offset 5-9
range and sensitivity C-2
viewing 5-4
acronyms, list of A-2
Activate button, System tab 5-8
adapter, Ethernet to USB E-6
air intake fan 2-4
air intake filter, cleaning 8-12
Alarm button, Main tab 5-4
Alarm In signal 4-5
Alarm Out signal 4-6
alarms
setting voltage state of 5-5, 5-6
viewing status of 5-4, 5-5
Alarms tab 4-5, 4-6, 5-5
Analog In signal 4-6
analog input and output 2-4, 4-2
Analog Out signal 4-6
anhydrous sodium chloride 6-2
Apply button, Constants dialog 5-11
aRI calibration constant field, Constants
dialog 5-9
aRI offset field, Constants dialog 5-9
aRI tab 5-4
aRI. See absolute RI
arrow keys 5-2
ASTRA software 3-3, E-18
calibration using 6-2
collecting data with 6-4
Audio Alarm On/Off button, Alarms tab 5-7
Auto Inject field, System tab 4-5
Auto Inject In signal 4-5
auto inject input and output 2-4, 4-2
Auto Inject Out signal 4-6
Auto Inject, System tab 5-8
cables
crossover E-5
Ethernet 4-7, E-5
for communication connections 3-3
for signal connectors 4-2
calibration 6-2
calibration constants
calculating 6-4
setting 5-9
Close button, Constants dialog 5-11
Close button, LED Intensity dialog 5-12
Collection interval, Constants dialog 5-10
colors, wire 4-3
prior versions D-2
columns, thermal control of 7-2
communication connections 2-4, 3-3, 4-7, 513
Communications tab 5-13, E-17
computer
connections to 2-4, 3-3, 4-7, 5-13
software for 3-3
condensation, preventing 4-8
Constants button, System tab 5-8
Constants dialog 5-9
contact information 1-4
CPU specification C-2
crossover cable E-5
B
baseline noise 9-4
beam deflection angle, measuring B-4
bubble in flow cell 9-2
Optilab rEX User’s Guide (M1500 Rev. D)
D
data collection for calibration 6-4
DAWN AUX analog input, connecting analog out cable to 4-3
defaults, resetting to 5-11
deflection based design B-2
deflection-based measurement 1-2
degassing 7-3
DHCP field 5-13, E-17
differential RI (dRI) 1-2
analog out calibration constant 5-10
analog out range 5-10
calibration constant 5-9
offset 5-9
range and sensitivity C-2
setting zero value of 4-5, 4-10, 5-4
Index-1
Index
value at minimum voltage 5-10
viewing 5-3
dimensions of Optilab rEX C-2
display. See LCD display
dn/dc value 6-2, 6-4
DNDC software 3-3
dRI analog out calibration constant field 510
dRI analog out range field 5-10
dRI at min voltage field 5-10
dRI calibration constant field 5-9
dRI measurements
methodology for 2-2
reading 2-2
dRI offset field, Constants dialog 5-9
dRI. See differential RI
dry gas pressure requirements 4-8
dry nitrogen connection 4-8
dry nitrogen purge port 2-4
dynamic range C-2
volume specifications C-2
See also sample; solvents
fluid leaks
alarm for 5-5, 5-6
cleaning 8-11
liquid leak port for 2-3
warning F-2
flushing (purging) Optilab rEX 3-2, 4-9
front panel 2-3, 5-1
Alarms tab 4-5, 4-6, 5-5
aRI tab 5-4
Communications tab 5-13
keyboard use with 5-2
Main tab 5-3
System tab 4-5, 5-7
front panel door 2-3
fuses, changing 8-12
E
H
G
guard column 7-3
eluent, thermal control of 7-2
ENTER key 5-2
error condition 9-4
ESC key 5-2
Ethanol, shipped with Optilab rEX 3-3, 4-9
Ethernet
cable E-5
communication 5-13
connecting via E-15
connector 2-4, 4-7
switch E-7
to USB adapter E-6
Ethernet port
on computer E-4
on instrument E-3
exhaust fan 2-4
External alarm IN alarm 5-6
External alarm IN field 5-5
External alarm OUT alarm 5-6
External alarm OUT field 5-6
Help button, Alarms tab 5-7
HPLC detection
in-line 7-2
off-line 6-2
HPLC fittings for fluid connections 3-2, 4-7
HPLC pump with injector 6-3
F
keypad 2-3, 5-2
fans 2-4
filtration of sample 7-3
firmware upgrades 8-13
flow cell
bubble in 9-2
conventional B-2
used by Optilab rEX B-3
fluid
connections 2-3, 3-2, 4-7
pressure 4-7
Index-2
I
ID tubing 6-3
IN port 2-3, 4-8, 4-9
injector 6-3
in-line operation 7-2
installation and setup 3-2, 4-1
installing software 3-3
Instrument Name field 5-13
instrument stability check 4-10
interval for collection 5-10
IP Address field, Communications tab 5-13
IP Settings field, Communications tab 5-13
ISI dialog in ASTRA V E-18
K
L
LAN
connecting to E-8
connecting via E-15
LAN connector E-4
LCD display 2-3, 5-1
Alarms tab 4-5, 4-6, 5-5
aRI tab 5-4
Communications tab 5-13
Optilab rEX User’s Guide (M1500 Rev. D)
Index
keyboard use with 5-2
Main tab 5-3
specifications for C-2
System tab 4-5, 5-7
leaks, fluid
alarm for 5-5, 5-6
cleaning 8-11
liquid leak port for 2-3
LED button, System tab 5-8
LED field, LED Intensity dialog 5-11
LED intensity
low light 5-12
optimal 5-12
LED Intensity dialog 5-11
LED light source
replacing 8-2
See light source
light intensity 5-12
Light Intensity field, LED Intensity dialog
5-12
light source
low light alarm 9-2
optimizing power for 5-11
replacing 8-2
setting power to 5-11
specifications for C-2
turning on or off 5-11
viewing current signal from 5-12
Liquid leak alarm, Alarms tab 5-6
liquid leak port 2-3
liquid leaks 8-11
logging in to wyatt.com 8-13
low light alarm 9-2
Low light alarm, Alarms tab 5-7
low-light threshold 5-12
M
Main tab 5-3
maintenance of Optilab rEX 8-1
Max voltage field, Constants dialog 5-10
Microsoft Windows
rebooting 9-4
service pack E-19
Min voltage field, Constants dialog 5-10
miniDAWN AUX analog input, connecting
analog out cable to 4-3
N
nitrogen connection 4-8
nitrogen pressure 5-6
Nitrogen pressure alarm, Alarms tab 5-6
Nitrogen pressure field, Alarms tab 5-6
nitrogen purge port 2-4
Optilab rEX User’s Guide (M1500 Rev. D)
noise
acceptable levels of 4-10
baseline, excessive 9-4
O
OFF field, LED Intensity dialog 5-11
off-line operation 6-2
ON field, LED Intensity dialog 5-11
Optilab rEX
calibration of 6-2
capabilities of 1-2, 2-2
front panel of 2-3, 5-1
in-line operation of 7-2
installation and setup 3-2, 4-1
instrument stability check for 4-10
maintenance of 8-1
off-line operation of 6-2
operating principles 2-2, B-1
purging (flushing) 3-2, 4-9
rear panel of 2-4, 4-2
specifications for C-1
thermal control of 7-2
Optimize button, LED Intensity dialog 511
OUT port 2-3, 4-8, 4-9
Overheated alarm, Alarms tab 5-6
P
Percent max power field 5-11, 8-3
photodetector, signal detected from 5-12
photodiode array B-4
photodiode, split B-4
pinging instrument E-19
power connections 2-4, 3-2, 4-2
power requirements 3-2, 4-2, C-2
power switch 2-3, 4-9
power warm up time 4-9
pressure
dry gas 4-8
fluid 4-7
maximum for cell C-2
maximum for system C-2
nitrogen 5-6
pump
HPLC pump with injector 6-3
requirements for 7-2
syringe pump 6-3
PURGE button, Main tab 4-9
Purge In signal 4-5
Purge mode 3-2
Purge Off button, Main tab 5-4
purge port, nitrogen 2-4
purging (flushing) Optilab rEX 3-2, 4-9
Index-3
Index
R
T
rear panel 2-4, 4-2
rebooting 4-9, 9-4
recycle activation 5-8
Recycle In signal 4-5
Recycle Out signal 4-6
Refractive Index (RI) detectors
capabilities of 1-2
See also Optilab rEX
response time C-2
Restore Factory Defaults button, Constants dialog 5-11
RI detectors. See Refractive Index detectors
RI measurements
methodology for B-2
See also aRI; dRI
RIU field, aRI tab 5-4
RJ-12 connectors 2-4, 4-2
pinouts for 4-2
prior versions D-2
signal function for 4-4, D-2
TAB key 5-2
temperature
default 3-2
for sample C-2
overheated, alarm for 5-6
regulation of C-2
setting 3-2, 5-3
viewing 5-3, 5-6
will not set below 20C 9-3
Temperature field, Alarms tab 5-6
Temperature Set field, Main tab 5-3
thermal control of Optilab rEX 7-2
Time field, System tab 5-8
troubleshooting
low light alarm 9-2
noisy baseline 9-4
temperature will not set below 20C 9-3
TTL (Transistor-Transistor Logic) inputs
and outputs 2-4, 4-2
tubing
between injector and Optilab rEX 6-3
for fluid connections 3-2, 4-7
for fluid leaks 2-3
for syringe pump infusion 6-3
S
sample
preparation of 6-2, 7-3
temperature control range for C-2
See also fluid; solvents
Serial number field, System tab 5-8
service pack 2, Microsoft Windows E-19
signal connectors 2-4, 4-2
software
installing 3-3
types of 3-3
Software version field, System tab 5-8
solenoid drive output 2-4, 4-2
solvents
changing 7-2
polarity of 3-3, 4-9
preparation of 7-2
requirements for 7-3
See also fluid; sample
specifications for Optilab rEX C-1
split photodiode B-4
stability check 4-10
standard Ethernet cable E-5
Static IP field 5-13, E-17
Subnet Mask field, Communications tab 513
syringe pump 6-3
System Constants field, Constants dialog
5-9
system crash 9-4
System tab 4-5, 5-7
Index-4
U
upgrades 8-13
USB port
connecting via E-12
on computer E-4
on instrument E-3
to Ethernet adapter E-6
V
Vapor alarm, Alarms tab 5-6
View field, Main tab 5-3
W
warm up time 3-2, 4-9
warnings F-1
waste activation 5-8
Waste/Recycle field, System tab 5-8
wavelength
replacing light source 8-2
Wavelength field, System tab 5-8
weight of Optilab rEX C-2
Windows operating system 9-4
service pack E-19
wire colors 4-3
prior versions D-2
Wyatt Technology, contact information for
1-4
wyatt.com 8-13
Optilab rEX User’s Guide (M1500 Rev. D)
Index
X
Z
x-axis field, Main tab 5-3
Zero button, Main tab 4-10, 5-4
Zero In signal 4-5
Zero selection 3-3
on auto inject signal 5-8
Y
y-axis field, Main tab 5-3
Optilab rEX User’s Guide (M1500 Rev. D)
Index-5
Index
Index-6
Optilab rEX User’s Guide (M1500 Rev. D)